when i switched my pc on it took ages to boot up and for some reason it wouldn't detect my hard drive. There was a message saying: "check system health!" I tried restarting and i got the same. I couldnt turn off my pc and so i had to resort to unplugging it at the back. but after i plugged the power lead back in the computer has ceased to respond, it wont even switch on. is it possible i may have blown my power supply? I have a feeling it may have been my CPU overheating that was causing the problems, i have an Athlon 2000+XP what is a dangerous temperature for this to reach and what happens if it does severely overheat?