The Windows 7 Memory Diagnostic Tool comes in handy if you suspect your RAM may be faulty, or even just to periodically double check that RAM is in fact fine.
The tool is nigh on impossible to locate but, thankfully, very easy to access (once you know how):
1) Click on Start and type mem into the Search dialogue box.
2) Now, in the list of results, click on Windows Memory Diagnostic.
That's all there is to it, you should now see the Windows Memory Diagnostic screen.
Of course, a tool built into Windows is not going to be of much use to you if the operating system will not boot. If the system will not boot and you suspect faulty RAM, you will need to use something like Memtest86, which will run memory diagnostics from bootable CD.
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