:frown: I am having the same problem, but it only started after I upgraded to WinXP! Random reboots occur during just about anything: Web browsing, starting up Counter-Strike (that one more than anything), even when I haven't touched it for hours. I am not overclocking anything, so that isn't an issue. I noticed that you also have XP, neutralizer. I tried the latest BIOS upgrade from my mobo mfr (MSI), but it didn't do anything. This was never an issue with Win 98 (shockingly). Any recommendations would be welcome. I considered increasing CPU voltage but don't want to fry the thing.
PIII 933 Mhz (not overclocked)
MSI 8326 (815 Pro)
256 MB PC133 SDRAM
Leadtek Winfast Geforce 2 Pro
300W Sparkle power supply
CPU runs around 39 degrees C when idle