What is Random Access Memory (RAM)?

Random Access Memory, or RAM (pronounced as ramm), is the physical hardware inside acomputer

that temporarily stores data, serving as the computer's "working" memory. Additional RAM allows a computer to work with more information at the same time, which usually has a dramatic effect on total system performance. Some popular manufacturers of RAM include Kingston, PNY, Crucial Technology, and Corsair. Note: RAM is also known as main memory, internal memory, primary storage, primary memory, memory "stick", and RAM "stick". Your Computer Needs RAM to Use Data Quickly Put simply, the purpose of RAM is to provide quick read and write access to a storage device. Your computer uses RAM to load data because it's much quicker than running that same data directly off of a hard drive. Think of RAM like an office desk. A desk is used for quick access to important documents, writing tools, and other items that you need right now. Without a desk, you'd keep everything stored in drawers and filing cabinets, meaning it would take much longer to do your everyday tasks since you would have to constantly reach into these storage compartments to get what you need, and then spend additional time putting them away. Similarly, all the data you're actively using on your computer (or smartphone, tablet, etc.) is temporarily stored in RAM. This type of memory, like a desk in the analogy, provides much faster read/write times than using a hard drive. Most hard drives are considerably slower than RAM due to physical limitations like rotation speed. RAM Works With Your Hard Drive (But They're Different Things) RAM is typically referred to simply as "memory" even though other types of memory may exist inside a computer. RAM, which is the focus of this article, has nothing at all to do with the amount of file storage a hard drive has, even though the two are often incorrectly interchanged with each other in conversation. For example, 1 GB of memory (RAM) isn't the same thing as 1 GB of hard drive space. Unlike a hard drive, which can be powered down and then back on without losing its data, the contents of RAM are always erased when the computer shuts down. This is why none of your programs or files are still open when you turn your computer back on. One way computers get around this limitation is to put your computer into hibernation mode. Hibernating a computer just copies the contents of RAM to the hard drive when the computer shuts down and then copies it back to tRAM when powered back on. Each motherboard supports only a certain range of memory types in certain combinations, so always check with your motherboard manufacturer before making a purchase. The RAM in Your Computer Resembles a Ruler or "Stick" A standard "module" or "stick" of desktop memory is a long, thin piece of hardware that resembles a short ruler. The bottom of the memory module has one or more notches to guide for proper installation and is lined with numerous, usually gold-plated, connectors. Memory is installed in memory module slots located on the motherboard. These slots are easy to find - just look for the small hinges that lock the RAM in place, located on either side of the similarly-sized slot on the motherboard. Important: Certain sizes of modules may need to be installed in certain slots, so always check with your motherboard manufacturer before purchase or installation! Memory modules come in various capacities and variations. Modern memory modules can be purchased in 256 MB, 512 MB, 1 GB, 2 GB, 4 GB, and 8 GB sizes. Some examples of the different types of memory modules include DIMM, RIMM, SIMM, SO-DIMM, and SO-RIMM. How Much RAM Do You Need? Just like with a CPU and hard drive, the amount of memory you need for your computer depends entirely on what you use, or plan to use, your computer for. For example, if you're buying a computer for heavy gaming, then you'll want enough RAM to support smooth gameplay. Having just 2 GB of RAM available for a game that recommends at least 4 GB is going to result in very slow performance if not total inability to play your games. On the other end of the spectrum, if you use your computer for light Internet browsing and no video streaming, games, memory-intensive applications, etc., you could easily get away with less memory. The same goes for video editing applications, programs that are heavy on 3D graphics, etc. You can normally find out before you buy a computer just how much RAM a specific program or game will require. It would be hard to find a new desktop, laptop, or even tablet that comes with less than 2 to 4 GB of RAM pre-installed. Unless you have a specific purpose for your computer apart from regular video streaming, Internet browsing, and normal application use, you probably don't need to buy a computer that has any more RAM than that. Troubleshooting RAM Issues The first thing you should do if you suspect an issue with one or more RAM sticks is to reseat the memory modules. If one of the RAM sticks hasn't been securely inserted into its slot on the motherboard, it's possible that even a small bump could knock it out of place and cause memory problems that you didn't have before. If reseating the memory doesn't improve the symptoms, I recommend using one of these free memory test programs. Since they work from outside the operating system, they work with any kind of PC - Windows, Mac, Linux, etc. Your best option is to replace the memory in your computer if one of these tools identifies a problem, no matter how small.

Add RAM and Internal Storage

Every time Apple releases a new Mac mini, you may wonder if your current Mac mini is still up to snuff. If you're trying to decide between buying a new Mac mini, or just upgrading your current mini to gain performance without spending too much money, then you've come to the right place. Intel Mac mini In this upgrade guide, we look at the Intel-based Mac minis that have been available since the first Intel Macs were introduced in early 2006. If you have one of the earlier PowerMac-based minis, you'll probably want to purchase a newer model. Even so, this upgrade guide can be of help by revealing what the upgrade options are for each Intel model. DIY? Maybe, Maybe Not Depending on the specific model of mini, both the RAM and the hard drive or SSD can be upgraded. It’s not always the easiest DIY upgrade, however. Once again, depending on the specific model, some upgrades may be as easy as removing a few screws and popping in some RAM. In other cases, a great deal of disassembly may be required, including using some tools not commonly found in most DIY toolkits. But you don’t really have to worry about the special tools; they're inexpensive, and readily available from the various retailers who sell Mac mini upgrade components. If you're having problems finding the needed tools I can suggest: iFixit selection of repair and upgrade tools. Other World Computing collection of toolkits and accessories. Multipurpose 41-piece toolkit for Apple products that is available from Amazon. If you're concerned about your DIY skills, you may wish to have an Apple specialist perform the upgrade for you. Most dealers offer this type of service. If you're a bit adventurous, you can perform these upgrades yourself, and save a bit of cash. Just be careful, and take it slow. If you do decide to tackle it yourself, I recommend performing both a RAM and a hard drive upgrade at the same time. You don't want to be taking your Mac mini apart on a regular basis, so doing everything at once is the best course of action. Find Your Mac mini's Model Number The first thing you need is your Mac mini's model number. Here's how to find it: From the Apple menu, select About This Mac. In the About This Mac window that opens, click the More Info button or the System Report button, depending on the version of OS X you're using. The System Profiler window will open, listing your mini's configuration. Make sure the Hardware category is selected in the left-hand pane. The right-hand pane will display the Hardware category overview. Make a note of the Model Identifier entry. You can then quit the System Profiler. RAM Upgrades All of the Intel Mac minis have two RAM slots. I recommend upgrading your Mac mini's memory to the largest configuration supported by your specific model. Because the upgrades are a bit difficult to perform, you don't want to have to go back and upgrade the RAM again at some future date. Be sure to check the information for your specific Mac mini model, below, for the correct type of RAM to use. Internal Hard Drive or SSD Upgrades Like the RAM upgrade, the hard drive upgrade is best suited to individuals who have a bit of computer DIY experience under their belts. Whether you're experienced or just adventurous, this is something you probably don't want to do more than once, so install the largest hard drive you can afford when you perform this upgrade. Mac mini Models The early Intel-based Mac minis predominantly used Intel Core 2 Duo processors of various speeds. The exceptions were the 2006 models with the Mac mini 1,1 identifier. These models used the Intel Core Duo processors, the first generation of the Core Duo line. The Core Duo processors use a 32-bit architecture instead of the 64-bit architecture seen in the Core 2 Duo models. Because of the lack of support for the 64-bit architecture, I don’t recommend investing any money in upgrading the original Mac mini 1,1.

what is Remote Desktop Protocol _RDP

                     

                

Remote Desktop Protocol (RDP) is a proprietary protocol developed by Microsoft, which provides a user with a graphical interface to connect to another computer over a network connection. The user employs RDP client software for this purpose, while the other computer must run RDP server software. Clients exist for most versions of Microsoft Windows (including Windows Mobile), Linux, Unix, OS X, iOS, Android, and other operating systems. RDP servers are built into Windows operating systems; an RDP server for Unix and OS X also exists. By default, the server listens on TCP port 1554[1] and UDP port 3389.[2] Microsoft currently refers to their official RDP client software as Remote Desktop Connection, formerly "Terminal Services Client". The protocol is an extension of the ITU-T T.128 application sharing protocol.[3]

Version 4.0
[edit] Based on the ITU-T T.128 application sharing protocol (during draft also known as "T.share") from the T.120 recommendation series, the first version of RDP (named version 4.0) was introduced by Microsoft with "Terminal Services", as a part of their product Windows NT 4.0 Server, Terminal Server Edition. The Terminal Services Edition of NT 4.0 relied on Citrix's MultiWin technology, previously provided as a part of Citrix WinFrame atop Windows NT 3.51, in order to support multiple users and login sessions simultaneously. Microsoft required Citrix to license their MultiWin technology to Microsoft in order to be allowed to continue offering their own terminal-services product, then named Citrix MetaFrame, atop Windows NT 4.0. The Citrix-provided DLLs included in Windows NT 4.0 Terminal Services Edition still carry a Citrix copyright rather than a Microsoft copyright. Later versions of Windows integrated the necessary support directly. The T.128 application sharing technology was acquired by Microsoft from UK software developer Data Connection Limited.[5][6]
Version 5.0
[edit] This version was introduced with Windows 2000 Server, added support for a number of features, including printing to local printers, and aimed to improve network bandwidth usage. Version 5.1[edit] This version was introduced with Windows XP Professional, included support for 24-bit color and sound. The client is available for Windows 2000, Windows 9x, Windows NT 4.0.[7] With this version, the name of the client was changed from Terminal Services Client to Remote Desktop Connection; the heritage remains to this day, however, as the underlying executable is still named mstsc.exe. Version 5.2[edit] This version was introduced with Windows Server 2003, included support for console mode connections, a session directory, and local resource mapping. It also introduces Transport Layer Security (TLS) 1.0 for server authentication, and to encrypt terminal server communications.[8] This version is built into Windows XP Professional x64 Edition and Windows Server 2003 x64 & x86 Editions. Version 6.0[edit] This version was introduced with Windows Vista and incorporated support for Windows Presentation Foundation applications, Network Level Authentication, multi-monitor spanning and large desktop support, and TLS 1.0 connections.[9]
Version 6.0
 client is available for Windows XP SP2, Windows Server 2003 SP1/SP2 (x86 and x64 editions) and Windows XP Professional x64 Edition. Microsoft Remote Desktop Connection Client for Macintosh OS X is also available with support for Intel and PowerPC Mac OS versions 10.4.9 and greater. Server 2012 can support RDC 6.0 or later. Version 6.1[edit] This version was released in February 2008 and is included with Windows Server 2008, as well as with Windows Vista Service Pack 1. The client is included with Windows XP SP3.[10] In addition to changes related to how a remote administrator connects to the "console",[11] this version has new functionality introduced in Windows Server 2008, such as connecting remotely to individual programs and a new client-side printer redirection system that makes the client's print capabilities available to applications running on the server, without having to install print drivers on the server.[12][13] Version 7.0[edit] This version was released to manufacturing in July 2009 and is included with Windows Server 2008 R2, as well as with Windows 7.[14] With this release, also changed from Terminal Services to Remote Desktop Services. This version has new functions such as Windows Media Player redirection, bidirectional audio, multi-monitor support, Aero glass support, enhanced bitmap acceleration, Easy Print redirection,[15] Language Bar docking. The RDP 7.0 client is available on Windows XP SP3 and Windows Vista SP1/SP2 through KB969084.[16] RDP 6.1 client and RDP 7.0 client are not supported on Windows Server 2003 x86 and Windows Server 2003 / Windows XP Professional x64 editions. RDP 7.0 is also not supported on Windows Server 2008. RDP 7.0 clients also do not support connecting to terminal servers running Windows 2000 Server.[17] Most RDP 7.0 features like Aero glass remote use, bidirectional audio, Windows Media Player redirection, multiple monitor support and Remote Desktop Easy Print are only available in Windows 7 Enterprise or Ultimate editions.[18][19] SP1 and Server 2008 R2 SP1. It adds RemoteFX functionality. Version 8.0[edit] This version was released in Windows 8 and Windows Server 2012. This version has new functions such as Adaptive Graphics (progressive rendering and related techniques), automatic selection of TCP or UDP as transport protocol, multi touch support, DirectX 11 support for vGPU, USB redirection supported independently of vGPU support, etc.[20][21] A "connection quality" button is displayed in the RDP client connection bar for RDP 8.0 connections; clicking on it provides further information about connection, including whether UDP is in use or not.[22] The RDP 8.0 client and server components are also available as an add-on for Windows 7 SP1. The RDP 8.0 client is also available for Windows Server 2008 R2 SP1, but the server components are not. The add-on requires the DTLS protocol to be installed as prerequisite.[22] After installing the updates, for the RDP 8.0 protocol to be enabled between Windows 7 machines, an extra configuration step is needed using the Group Policy editor.[23] A new feature in RDP 8.0 is limited support for RDP session nesting; it only works for Windows 8 and Server 2012 though, Windows 7 and Server 2008 R2 (even with the RDP 8.0 update) do not support this feature.[24] The "shadow" feature from RDP 7, which allowed an administrator to monitor (snoop) on a RDP connection has been removed in RDP 8. The Aero Glass remoting feature (applicable to Windows 7 machines connecting to each other) has also been removed in RDP 8.[21][22] Version 8.1[edit] This version was released with Windows 8.1 and Windows Server 2012 R2. A RDP 8.1 client update exists for Windows 7 SP1 as well, but unlike the RDP 8.0 update for Windows 7, it does not add a RDP 8.1 server component to Windows 7. Furthermore, if RDP 8.0 server function is desired on Windows 7, the KB 2592687 (RDP 8.0 client and server components) update must be installed before installing the RDP 8.1 update.[25][26] Support for session shadowing was added back in RDP version 8.1. This version also fixes some visual glitches with Microsoft Office 2013 when running as a RemoteApp.[25] Version 8.1 of the RDP protocol also enables a "restricted admin" mode. Logging into this mode only requires knowledge of the hashed password, rather than of its plaintext, therefore making a pass the hash attack possible.[27] Microsoft has released an 82-page document explaining how to mitigate this type of attack.[28] Version 10.0[edit] Version 10.0 of the RDP protocol includes the following new features: AutoSize zoom (useful for HiDPI clients).[29] In addition graphics compression improvements were included utilizing H.264/AVC.[30] Features[edit] 32-bit color support. 8-, 15-, 16-, and 24-bit color are also supported. 128-bit encryption, using the RC4 encryption algorithm, as of Version 6.[31] Audio Redirection allows users to process audio on a remote desktop and have the sound redirected to their local computer. File System Redirection allows users to use their local files on a remote desktop within the terminal session. Printer Redirection allows users to use their local printer within the terminal session as they would with a locally- or network-shared printer. Port Redirection allows applications running within the terminal session to access local serial and parallel ports directly. The remote computer and the local computer can share the clipboard. Microsoft introduced the following features with the release of RDP 6.0 in 2006: Seamless Windows: remote applications can run on a client machine that is served by a Remote Desktop connection. It is available since RDP 6.[32] Remote Programs: application publishing with client-side file-type associations. Terminal Services Gateway: enables the ability to use a front-end IIS server to accept connections (over port 443) for back-end Terminal Services servers via an https connection, similar to how RPC over https allows Outlook clients to connect to a back-end Exchange 2003 server. Requires Windows Server 2008. Network Level Authentication Support for remoting the Aero Glass Theme (or Composed Desktop), including ClearType font-smoothing technology. Support for remoting Windows Presentation Foundation applications: compatible clients that have .net framework 3.0 support can display full Windows Presentation Foundation effects on a local machine. Rewrite of device redirection to be more general-purpose, allowing a greater variety of devices to be accessed. Fully configurable and scriptable via Windows Management Instrumentation. Improved bandwidth tuning for RDP clients.[citation needed] Support for Transport Layer Security (TLS) 1.0 on both server and client ends (can be negotiated if both parties agree, but not mandatory in a default configuration of any version of Windows). Multiple monitor support for allowing one session to use multiple monitors on the client (disables desktop composition) Release 7.1 of RDP in 2010 introduced the following feature: RemoteFX: RemoteFX provides virtualized GPU support and host-side encoding; it ships as part of Windows Server 2008 R2 SP1.

What Is a Proxy or Proxy Server

A proxy or proxy server is basically another computer which serves as a hub through which internet requests are processed. By connecting through one of these servers, your computer sends your requests to the proxy server which then processes your request and returns what you were wanting. In this way it serves as an intermediary between your home machine and the rest of the computers on the internet. Proxies are used for a number of reasons such as to filter web content, to go around restrictions such as parental blocks, to screen downloads and uploads and to provide anonymity when surfing the internet.

Why Use a Proxy?

If you are wanting to surf the web anonymously then proxies can provide you with a means to hide your home IP address from the rest of the world. By connecting to the internet through proxies, the home IP address of your machine will not be shown but rather the IP of the proxy server will be shown. This can provide you with more privacy then if you were simply connecting directly to the internet. There are number of proxies that can provide you with service. You can find a list of these simply by typing "Proxy List" into any search engine. There are some proxies which are free and some which charge money, the choice is up to you but we have found that the paid proxies are more reliable, faster and more secure.

                                 What is Linux

Linux is the best-known and most-used open source operating system. As an operating system, Linux is software that sits underneath all of the other software on a computer, receiving requests from those programs and relaying these requests to the computer’s hardware. For the purposes of this page, we use the term “Linux” to refer to the Linux kernel, but also the set of programs, tools, and services that are typically bundled together with the Linux kernel to provide all of the necessary components of a fully functional operating system. Some people, particularly members of the Free Software Foundation, refer to this collection as GNU/Linux, because many of the tools included are GNU components. However, not all Linux installations use GNU components as a part of their operating system. Android, for example, uses a Linux kernel but relies very little on GNU tools.

How does Linux differ from other operating systems?.

In many ways, Linux is similar to other operating systems you may have used before, such as Windows, OS X, or iOS. Like other operating systems, Linux has a graphical interface, and types of software you are accustomed to using on other operating systems, such as word processing applications, have Linux equivalents. In many cases, the software’s creator may have made a Linux version of the same program you use on other systems. If you can use a computer or other electronic device, you can use Linux. But Linux also is different from other operating systems in many important ways. First, and perhaps most importantly, Linux is open source software. The code used to create Linux is free and available to the public to view, edit, and—for users with the appropriate skills—to contribute to. Linux is also different in that, although the core pieces of the Linux operating system are generally common, there are many distributions of Linux, which include different software options. This means that Linux is incredibly customizable, because not just applications, such as word processors and web browsers, can be swapped out. Linux users also can choose core components, such as which system displays graphics, and other user-interface components.

What is the difference between Unix and Linux?

You may have heard of Unix, which is an operating system developed in the 1970s at Bell Labs by Ken Thompson, Dennis Ritchie, and others. Unix and Linux are similar in many ways, and in fact, Linux was originally created to be similar to Unix. Both have similar tools for interfacing with the systems, programming tools, filesystem layouts, and other key components. However, Unix is not free. Over the years, a number of different operating systems have been created that attempted to be “unix-like” or “unix-compatible,” but Linux has been the most successful, far surpassing its predecessors in popularity.

what is c# ?

C# is designed to be a platform-independent language in the tradition of Java (although it is implemented primarily on Windows). It's syntax is similar to C and C++ syntax, and C# is designed to be an object-oriented language. There are, for the most part, minor variations in syntax between C++ and C#. Main has no return type, there are no semicolons after class names, there are some (to C++ programmers) strange decisions regarding capitalization - such as the capitalization of Main. Other a few differences, the syntax is often the same. This decision is reasonable, in light of the fact that C syntax has been used with several other languages - notably Java. Similar to Java, C# does not support multiple inheritance; instead it provides Java's solution: interfaces. Interfaces implemented by a class specify certain functions that the class is guaranteed to implement. Interfaces avoid the messy dangers of multiple inheritance while maintaining the ability to let several classes implement the same set of methods. Another helpful feature of C# is garbage collection. Therefore, it is unnecessary to include a destructor for each class unless a class handles unmanaged resources; if so, it's necessary to release control those resources from within the class (The Finalize function is used to clear up these unmanaged resources; it can even be abbreviated with the same syntax as a C++ destructor). Of course, C# also provides direct access to memory through C++ style pointers, but these pointers are not garbage collected until specifically released by the programmer. C#, as part of the .NET framework, is compiled to Microsoft Intermediate Language (MSIL), which is a language similar to Java's bytecode. MSIL allows C# to be platform independent and runs using just in time compiling. Therefore programs running under .NET gain speed with repeated use. Furthermore, because the other languages that make up the .NET platform (including VB and Cobol) compile to MSIL, it is possible for classes to be inherited across languages. The MSIL, like bytecode, is what allows C# to be platform independent. The potential for C# is great if the .NET platform succeeds. C# is designed to take advantage of the design of .NET, and Microsoft has poured a great deal of money into .NET. Do you need to learn C#? If you know C++, you'll probably be able to pick it up quickly, and yes,

you can still use C++ with .NET. It's important to keep an eye on C# to see how it will affect you.

RAM

Random Access Memory, or RAM (pronounced as ramm), is the physical hardware inside acomputer

that temporarily stores data, serving as the computer's "working" memory. Additional RAM allows a computer to work with more information at the same time, which usually has a dramatic effect on total system performance. Some popular manufacturers of RAM include Kingston, PNY, Crucial Technology, and Corsair. Note: RAM is also known as main memory, internal memory, primary storage, primary memory, memory "stick", and RAM "stick". Your Computer Needs RAM to Use Data Quickly Put simply, the purpose of RAM is to provide quick read and write access to a storage device. Your computer uses RAM to load data because it's much quicker than running that same data directly off of a hard drive. Think of RAM like an office desk. A desk is used for quick access to important documents, writing tools, and other items that you need right now. Without a desk, you'd keep everything stored in drawers and filing cabinets, meaning it would take much longer to do your everyday tasks since you would have to constantly reach into these storage compartments to get what you need, and then spend additional time putting them away. Similarly, all the data you're actively using on your computer (or smartphone, tablet, etc.) is temporarily stored in RAM. This type of memory, like a desk in the analogy, provides much faster read/write times than using a hard drive. Most hard drives are considerably slower than RAM due to physical limitations like rotation speed. RAM Works With Your Hard Drive (But They're Different Things) RAM is typically referred to simply as "memory" even though other types of memory may exist inside a computer. RAM, which is the focus of this article, has nothing at all to do with the amount of file storage a hard drive has, even though the two are often incorrectly interchanged with each other in conversation. For example, 1 GB of memory (RAM) isn't the same thing as 1 GB of hard drive space. Unlike a hard drive, which can be powered down and then back on without losing its data, the contents of RAM are always erased when the computer shuts down. This is why none of your programs or files are still open when you turn your computer back on. One way computers get around this limitation is to put your computer into hibernation mode. Hibernating a computer just copies the contents of RAM to the hard drive when the computer shuts down and then copies it back to tRAM when powered back on. Each motherboard supports only a certain range of memory types in certain combinations, so always check with your motherboard manufacturer before making a purchase. The RAM in Your Computer Resembles a Ruler or "Stick" A standard "module" or "stick" of desktop memory is a long, thin piece of hardware that resembles a short ruler. The bottom of the memory module has one or more notches to guide for proper installation and is lined with numerous, usually gold-plated, connectors. Memory is installed in memory module slots located on the motherboard. These slots are easy to find - just look for the small hinges that lock the RAM in place, located on either side of the similarly-sized slot on the motherboard. Important: Certain sizes of modules may need to be installed in certain slots, so always check with your motherboard manufacturer before purchase or installation! Memory modules come in various capacities and variations. Modern memory modules can be purchased in 256 MB, 512 MB, 1 GB, 2 GB, 4 GB, and 8 GB sizes. Some examples of the different types of memory modules include DIMM, RIMM, SIMM, SO-DIMM, and SO-RIMM. How Much RAM Do You Need? Just like with a CPU and hard drive, the amount of memory you need for your computer depends entirely on what you use, or plan to use, your computer for. For example, if you're buying a computer for heavy gaming, then you'll want enough RAM to support smooth gameplay. Having just 2 GB of RAM available for a game that recommends at least 4 GB is going to result in very slow performance if not total inability to play your games. On the other end of the spectrum, if you use your computer for light Internet browsing and no video streaming, games, memory-intensive applications, etc., you could easily get away with less memory. The same goes for video editing applications, programs that are heavy on 3D graphics, etc. You can normally find out before you buy a computer just how much RAM a specific program or game will require. It would be hard to find a new desktop, laptop, or even tablet that comes with less than 2 to 4 GB of RAM pre-installed. Unless you have a specific purpose for your computer apart from regular video streaming, Internet browsing, and normal application use, you probably don't need to buy a computer that has any more RAM than that. Troubleshooting RAM Issues The first thing you should do if you suspect an issue with one or more RAM sticks is to reseat the memory modules. If one of the RAM sticks hasn't been securely inserted into its slot on the motherboard, it's possible that even a small bump could knock it out of place and cause memory problems that you didn't have before. If reseating the memory doesn't improve the symptoms, I recommend using one of these free memory test programs. Since they work from outside the operating system, they work with any kind of PC - Windows, Mac, Linux, etc. Your best option is to replace the memory in your computer if one of these tools identifies a problem, no matter how small.