I have WinXP, on BX Master MB, CPU at 500 Hz
When booting, all tests are normal, fans are spinning and system temperature is all OK. Then, when I try accessing programs, internet or just browsing through my computer, the system freezes and reboots itself in about 10 sec. Occasionally, it emits a beep before rebooting. I've changed the hard drive and the problem is still there, also checked my DIMMs, no improvement.
PS I figured that my computer does not freeze/reboot untial I start browsing the web and my computer. The exact thing happens when I do this with another harddrive.