Booting up into BSOD

[Larry]

Hi guys. Since my last format, my computer has been running the best that it's ever been, until a few days ago. For some reason, it would randomly boot up into a BSOD screen. I'm able to press CTRL-ALT-DEL, and the system would reboot. It would then ask me to start up in safe mode. Instead I try and boot up regularly, and it would work! Not sure exactly why, but I'm thinking that it might be heat realated. Any suggestions???

Thanks!

Hardware:
PIII 450Mhz
192MB RAM
Matrox G400Max
SB Live!
ABit BF6 Mobo