RTFMTech.net/troubleshooter

Section 3: System Diagnostics

Important!
If you have not already done so, you should prepare a copy of the Ultimate Boot CD. Instructions for doing so can be found in the tools and software introduction.

Memory Testing - The first test that you need to run is called Memtest86+. It is an advanced memory diagnostic that will attempt to determine if you have a faulty memory module in your system. When you select to boot Memtest86+, the program will automatically load and begin running a series of tests. Let Memtest86+ run for at least an hour (or about 10 passes).

Hard disk testing - Hard disk are prone to mechanical and electrical failures that may masquerade as other types of problems. It is always a good thing to test your hard disk when you are experiencing random crashes or slowness. Load up the UBCD and run the Hitachi Drive Fitness test. I know you might be thinking, "I don't have a Hitachi drive!?" and while that may be true, the Drive Fitness Test or DFT is one of the most stable and trustworthy of the hard drive utilities out there. I suggest running dft first. Next, run the manufacturer's tool. If the results match up, you know exactly what is going on.

Proceed to next section: 4. Software Diagnostics