Memtest86

Memtest86 (www.memtest86.com)
Memtest86 is a RAM reliability tester. The underlying thesis is that a correctly-functioning computer should be able to store data in the RAM with 100 per cent accuracy. If it does not, then it will be unstable and prone to crashes.

Memtest86 is designed to stress-test the computer’s RAM for errors. It is designed to run from a bootable floppy disk or CD-ROM, or from a suitable bootstrap loader, without an operating system being present. The tests are sufficiently harsh for it to find otherwise unrecognized problems on machines that appear to work normally.

Installation
For a Windows installation, you need to download either the Pre-Complied Windows package, for building a bootable floppy disk, or an ISO (Zip version) to create a bootable CD. After the file download is complete, you decompress the file(s). To extract, right-click on the downloaded file and select the “Extract All” option. The extract option will let you choose where the files will be extracted to.

To build a bootable floppy, insert a floppy in the drive, then go to the folder where the files were extracted and click on the Install icon. Once the install is complete, the floppy disk will appear to be unformatted by Windows.

To build a bootable CD, use your CD burning software to create an image from the unzipped ISO file.

Since Memtest86 is a standalone program, it dose not require any operating system support for execution. It can be used with any PC regardless of what operating system, if any, is installed.

Features
Memory Sizing
This is one of the major features of Memtest85. The BIOS in modern PCs often reserves several sections of memory for its use, and also to communicate information to the OS. It is just as important to test these reserved memory blocks as it is for the reminder of the memory. For properly regardless of what the eventual use is. Memtest86 tests these reserved areas of memory.

Testing Algorithms
The algorithms resort to a set of nine different tests that have been arranged in a order to detect the maximum errors in the minimum time.

How to use it
Memtest86 needs to be run for several hours to fully evaluate the RAM. The best way to use the system is to set it up to run overnight, for a fully rigorous test. This will allow Memtest86 to run long enough to achieve full (read: 100 per cent) coverage, and identify RAM that frequently corrupts the data written to it.

If Memtest86 finds an error, it will stop and report it. If there is an error, you should consider replacing you RAM, or at the very least, verifying that your machine is correctly configured.