Hi! I recently got a freebie from my neighbor who is an OEM compu-dealer. I got a Tyan S2090 mobo with a P4 Socket 478 2.8Ghz cpu (no HT). Here's whats weird... I already had a working system, but i just swapped the mobo and cpu out with the new one and it "sort of" worked. The first time i started it up, I was able to login to Win XP and when it started to locate drivers and stuff like that, it spontaneously rebooted! So I started it up again. It rebooted again, but not until it VERY quickly flashed a blue screen error, this time BEFORE I logged in. Now I thought this was very strange... So I decided to Reinstall Windows, because I figured that would solve any conflicting hardware drivers that might be conflicting. But I couldn't - The installation stalled and told me my system wasn't fully ACPI compliant. So I checked out my mobo manual, and it turns out that the motherboard will only support up to 2.4Ghz P4! BUT, I'm not convinced that it is the problem. I'm just surprised that my computer did ANYTHING with too fast of a chip. I'm baffled at how the system could function at all. Could someone confirm my suspicion for me? If an incorrrect chip was installed would the system be unable to function, or is this normal for the circumstances? Thank you all in advance and happy belated holidays to you.