Corrupt Graphics & Crazy Colors in XP

It sounds to me like you've been spending too much time chasing down pints at The Coquitlam Inn, but if Roddy approves, I'll give you a pass too.

I just looked up your machine and see it used a 266MHz 2100+. It also appears that Compaq released a couple of others with this same motherboard using a 2400+ and a 2600+ Athlon XP so you may have a little flexibility. Unfortunately that Compaq BIOS is going to be somewhat crippled otherwise you could try manually increasing the core voltage in an attempt to resolve your problem. But, hold on - it gets worse. I couldn't open your last link re: the diagnostic failure but I'm not so sure this can be pinpointed to the CPU - it could be the board itself.