More problems with my Misfit Computer.  I thank you all for 4 pages of advice but the problem stands.

All of the following have caused my computer to crash, logging into my account, clicking shut down, starting a game, loading a BF2 map, exiting a game, clicking on don't send error report, and yes going to the bathroom .  I was having computer crashes constantly so I reinstalled windows Xp.  Fresh operating system and the problems continue.  I ran mem test and got 7 errors in the process of allocating memory before the test began .  Also ran MemTest86 and it really surprised me!  Every test was failed in the same way, both ram and cpu cache.  The program inserts a value in memory and then reads it to see if they match.

Wrote 0000 0000 to mem, 0000 0001 was read back.
Wrote 1010 1010 to mem, 1010 1011 was read back.
Wrote 6789 ABCD to mem, 6789 ABCE was read back.

CheckDisk reports a clean file system.  Memory errors found with any mem stick in any possable configuration.  At the moment booting windows normally causes it to crash before the login screen, and booting in safe mode sometimes hangs until it crashed or sometimes succeeds in loading safe mode.  I have an opinion about the problem but I wish to hear your thoughts.

No I have not...
The power supply is only half a year old 500 watt antec that replaced a different power supply who's fan stopped spinning and lead to overheating, possably more?

I don't remember if the problem with the original supply came to my attention by crashes or errors  .  But I do remember hearing the CPU fan roaring and I put my hand over the power supply fan to feal the temperature of the air, only to realize there was no air flow.  I can't recall if the computer was stable with the old power supply.  Its hard to disquingsh because this computer has had problems for 2-3 years.

This is no joke,  after the computer crashed 2 dozen times in a day I had the terrable misfortune of having my dreams crash on me in my sleep!  I can't emphasize enough the fustration I had in that dream. 

maybe a bad scratch in the PCB?

you never know...

Sales associate sold us MoBo and CPU combo & RAM combo
MSI PT880 Neo-FSR
"Pentium 4 3E GHz" with hyperthreading

All systems with in acceptable limits captain!
3GHz processor at 3013MHz - default and correct 1.36Vcore (but it varies from 1.31 - 1.41)
200MHz FSB MoBo at 203MHz FSB
1:1 FSB to RAM ratio
PC-3200 (200MHz "quad-pumped") at 203MHz
2.6V RAM at 2.6V
CPU-Z confirms memory running at its default and correct timings of 3-3-3-8 (Im making best guess cause computer is down)

During 3:2 FSB to where the ram runs at 166MHz with slightly tighter timings I have errors. So I set the ram to 1:1 200MHz and timings to 5-5-5-12 and still got memory errors.  This digital cam photo was taken with no tweaking done to the system.  Im looking up stride38 test on google which got zero erros on both test passes. http://oca.microsoft.com/en/windiag.asp#top

My best non conclusive data so far!   I had MemTest scan 200MB of the 512MB Kingston ram sticks, the rest was either used by windows or idle.

Mem stick A:
            Diagnostic in DOS        MemTest in WindowsXP
Slot 1          5586 errors                0 errors, windows crash, boot crash, and corrupt error report
Slot 2          5622 errors                3% test complete with 100+ errors
Slot 3          5686 errors                failed to load windows, hung

Mem stick B:
            Diagnostic in DOS        MemTest in WindowsXP
Slot 1          0 errors                     1 error, and windows crash
Slot 2          0 errors                     0 error, and windows crash
Slot 3          0 errors                     1 error

Scientific conclusion: "Mem stick A" is  , but still the crash with the good(er) mem stick is puzzling.
This message is brought to you by, "the Gooder Mem Stick" (running windows on 512MB)

try to swap video card