ok here's my situation: i have an amd tbird 900mhz on an asus a7v mb .. i built it maybe a month ago, it ran fine until yesterday - my boss asked me if i could try his 800mhz tbird in my system so that he could see if his was working properly, since his new system was giving him problems, and he had no other processor to test on his board instead, so when i got home i put the chip in, no big deal right? chip worked fine, system booted and ran perfectly - but here's the problem, after i put my 900 cpu back in, my system started behaving very abnormally, 9 out of 10 times trying to boot it up all the diagnostics appear as normal, but just before windows finishes loading it displays the following: "windows protection error. you must restart your computer..." - and the few times it did load properly (out of many tries) any high end applications i run crash in less than a minute or two, then after getting the computer to boot up again i ran only lower requiring programs like browser and irc, and the computer ran fine for the remainder of the day, but when i woke up this morning it was blue screened with windows having had an error .. computer boots up without any trouble into safe mode, but since i have no idea what is wrong i couldn't exactly do anything to fix it - even more odd, if i put his cpu back in it functions normally! and i know my cpu isn't overheated or anything either, because i've always checked the temp - so anyway, any suggestions would be very greatly appreciated, thanks