Ok, been struggling with this one for a few days now and as there is a lot of computer knowledge floating around in this great site of ours I thought I would ask for help.
I am upgrading 3 family PC's and decided to put AMD 64x2 4600 chips in them with new motherboards and RAM. I bought the gear for them and decided to spend yesterday and today building them.
Well I built 2 of them with no problems at all. Installed XP and they run like a dream

But the 3rd system.....it is a nightmare. It is identical to the one I am using myself (and as you can see from the fact that I am posting it works ok). Same power supply, case, graphics etc etc..the only difference being that I am using a SATA HDD on mine and an IDE 80GB on the other.
When I try to install XP it sometimes will crash at random spots and just reboot itself. I have managed a complete install but then find that it wont open device manager or random other programs etc....very unstable.
I have installed to the IDE HDD on this machine and all seemed well, tranfered said HDD to the other machine and I get the instability again very soon. I have tried various HDD and just about every combination possible to try an eliminate what the fault could be....but no joy.
My PC knowledge is very limited when it gets this far in and I am at a loss to figure what is going wrong

Worse still this is S.W.M.B.O's PC that we are talking about...she is not a happy bunny!!
My thoughts (please ignore the ignorance of a non tech mind)
1) Could it be XP related? using SP1 but a 64x2 chip? (32 bit as opposed to 64bit)
2) Could it be the IDE HDD? (although it seemed to work in my pc)
3) Could it be an instability on the motherboard? How could I tell?
4) Could it be that I should throw the PC out and concentrate on my Omega instead?
Any advice would be appreciated as I really dont have a clue :-/
Dave