Windows xp pro x64 keeps rebooting at startup

[cris]

Hi guys and gals, please help

I have had this problem twice now, my pc locked up,i couldnt do anything ,I had to hit the of switch.
I thought it was a virus but Idont think it is.

I thought it could of been hardware problems,I have a seperate drive with vista on it and it works fine!

Everytime I boot the my pc with the xp drive I get to the welcome screen and a error comes up for a spit second and it reboots and just keeps rebooting.
even in safemode it just keeps rebooting.

I tried to do a re-install it was going fine,it installed fine rebooted and enter thje setup process untill it got about 3/4 the way through the setup, and guess what! a error came up and rebooted th pc.

Im stuck I think its a registry problem but Im not really shure how to fix it Im a bit of a computer dummie if you know what i mean!

That stuff Is a bit out of my league

If anyone coud help Ill buy ya a beer!

 

[Tmagic650]

You are running XP Pro 64 bit. Is Vista 64 bit too?

 

[cris]

Yeah both operating systems are 64bit,the xp x64 was running sweet and all of a sudden it just locked up and I couldnt do a thing.so I had to hit the switch.now when I start the pc It keeps going through the setup for windows and gets to the same point and and reboots at the same spot all the time.

 

[Tmagic650]

You have a hardware fault, but I don't understand why Vista functions

 

[cris]

Why you say that !

the same thing happened about 6 moths ago I could not do a thing all,I could do was reformate and Its been running sweet scince untill a couple of days ago when It locked up. now its in a cycle of rebooting, I haven changed any hardware setting at all. apart form buying a second HD 320g seagate sate2 and putting Vista ultimate on it, but thats been in there for about three months,I have managed to get into the HD and save my music and pics
but I really dont want to formate,it It just takes so long to set my pc to where i want it.