Every computer has a place that stores programs to be used at a later time, known as random access memory (RAM). RAM can be found on small rectangle chips that slide into slots on the motherboard. Just like any other piece of equipment, memory can fail. A memtest procedure is the first step toward performing a memory test on your computer.
Computer technicians replace memory chips all the time when working on computers. This is why a memory test needs to be done on a regular basis, to make sure memory is good. If a memory chip should fail, it may prevent your system from booting or running.
When performing a memory test, you will find that most computers have a memory tester built into the PC's basic input-output system (BIOS). The BIOS is also on a chip, known as read-only memory (ROM). You can access the BIOS by means of a set up program. This program is usually accessed by hitting the F1, F2, Delete, or CTRL, ALT, ENTER keys, depending on the type of system you have.
When you turn on your PC, the BIOS will run the tester program automatically and scan the RAM. This is also referred to as a memtest procedure. After the memtest is completed, the computer may beep once or twice to warn of any problems, with an error code popping up on the screen. If there are no problems, the boot up process continues until the operating system loads and the desktop is reached.
Memory is always tested this way, but there are diagnostic utility programs available that can be more aggressive in performing a memory test. You can find many PC memory testing and diagnostic utility programs on the Internet. Some of them are free while others cost money.
If you do download one of these programs, it is best to burn the program on a bootable CD or DVD, and restart your PC, keeping the CD or DVD in the player. When your PC reboots, the CD or DVD will run and boot the testing program. Most programs will run diagnostic procedures that will aggressively test the computer's memory. The program will read and write the RAM several times to make sure that the RAM can hold the data. If there are no problems, the program reports no errors, and either returns control back to you so you can remove the disk and reboot the PC,or the PC continues in its boot process.
During the memory test, if a chip is found faulty, the program will stop and report its findings. At that time you will have to replace the defective chip. If the defective chip is not known, you may need to swap out one chip at a time, until you find the faulty one.