The worst kind of computer problems are the random, inexplicable ones that defy prediction or analysis. One minute everything's fine, then--bam!--you're stunned as you watch a Blue Screen of Death pop up and write out a crash dump file. When things like this start happening often, it's time to break out some basic memory diagnostic tools and get to work isolating the problem.
Bad computer memory is one of the three main reasons for random system failures; the other two are heat (usually caused by fans or heat-sinks being blocked with dust) and bad power. I've written before about a number of different computer memory test suites (e.g., Memtest86), but now Microsoft has one of its own, called, simply, Windows Memory Diagnostic.
The Windows Memory Diagnostic works like other computer memory test programs in that it does not run from within Windows itself. It installs onto a floppy disk (the installation program creates the disk) or runs as an ISO 9660 image burned to a CD-ROM. When booted, it provides you with the options to run either standard or extended memory tests, the latter being more exhaustive (and taking far longer to run) than the former. Usually, if there is an error, the system will be able to pinpoint which memory module the error is in.
Windows Memory Diagnostic also lets you toggle the use of the processor's cache; testing with the cache off is more thorough and precise but takes longer. This option can also be used to determine if a memory problem exists with the on-chip cache memory rather than the system memory. The user can also opt for whether to use the standard or extended memory map when testing (as you might surmise, the latter takes longer but is more thorough).
One caveat: Currently, Windows Memory Diagnostic cannot test a system with more than 4GB of RAM. If it's run on a system with more than 4GB, only the first 4GB will be tested. It also cannot test computer memory for systems with 64-bit processors.
About the author: Serdar Yegulalp is editor of the Windows Power Users Newsletter. Check it out for the latest advice and musings on the world of Windows network administrators -- and please share your thoughts as well!
More information on this topic:
- Tip: Blue screen of death appears; no discernible cause
- Topic: FAQ: Hardware Troubleshooting
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