please help... intel cpu + winXP

[mfa]

I'm looking for help troubleshooting an odd situation.

OS: winXP pro (legal copy)
main board: ASUS p4c800 deluxe
cpu: intel 3.0ghz, hyperthread, 800mhz fsb socket 478
psu: thermaltake silent purepower 480W
memory: 1gb kingmax (2x512mb)
hdd: 120gb maxtor SATA
video: geforce 6800 GT
sound: sb live 5.1


What happens:
I power up computer, and when it starts loading winxp - ie blue bar cycling - it will sometimes turn itself off. Sometimes. If not, it will turn off within about 2 minutes of use. I mean turn itself off as in it reached out and unplugged itself. I have tried a friend's 2.0ghz (no HT) cpu and it works just fine. I have downclocked my cpu to about 2.0ghz, and this seems to work, as long as I turn off hyperthreading.
This computer used to work perfectly for over a year, and now this. I have had my MB and CPU replaced through ASUS and Intel's warranty, tried different video cards, power supplies, even cdroms and hdds, and still cant get the 3.0ghz I paid for to work again - with WinXP Pro.
One more thing, I write this from my computer - fully functioning at 3.0 with HT enabled, with firefox and Fedora Core 4 installed. Seems like some sort of software issue with XP, an update bug maybe??

Has anyone else had this problem? I have heard of the hyperthread issue, which is why the 1st thing I tried was turning it off. This still wont explain why it worked for over 1 year then stopped. I'm really stuck on what to do next.

Any help or link(s) to help would be much appreciated.

 

[Nitestick]

any hardware changes. did you reformat and re-install or anything like that before the problem started occurring

 

[killians45]

can you run in safe mode with no problem?

 

[mfa]

thanks for responses....

- Only 1 hareware change, that was to get the 6800 card. the computer ran fine for about 8 months before this problem.
- I have tried to reinstall winXP, but it crashes durring installation. Fedora Core 4 did not crash when installing, and seems to run fine.
- Also, safe mode wont work porperly, but I will be trying that again with HT off just to be sure.

thanks again, any more ideas would be helpfull also

 

[RicoDirenzo]

Did you do the bios flash update on that Asus board? I had the same board and I would not function properly without doing the msot current Bios update from Asus: http://support.asus.com/download/download.aspx?SLanguage=en-us. The reason yoju are having to underclock that CPU is your bios. I had the non-delux version of this board and the 800fsb prescott ht needed a biso update for function @ 800mhz fsb.

 

[mfa]

thanks for the suggestion...

A friend of mine also got me to try the bios update, and it seemed to have no effect. Also, the chip is not a 'prescot' label and I have had the cpu since I bought it with the MB (it worked before any updates were out). I rolled bach the bios update for now, because these kinds of things happen from time to time CAUSED by the updates. I will see if there is an even newer bios update for the board though.

thank you