Memtest86+ is a very popular tool with system administrators who need to see if a machine is suffering from RAM issues.
The original program was not entirely compatible with the latest processors and 64bit chipsets hence the release of Memtest86+ which us a remake of the original program. From now on, it will be updated regularly too to ensure that it's compatible with the latest processors.
Memtest86+ is completely independent of the operating system and so it must be booted from the CD drive or a floppy disk drive. Burn the bootable disk image to disk, change your BIOS to boot-up via CD and Memtest86+ will kick into action. If you don't know how to read RAM readouts, then the results won't mean much although you can easily see how much RAM you have installed.
Extremely quick and easy to use, you can see why Memtest86+ is still hugely popular with network administrators for tracing memory problems.