I have been having BSOD reboots. Event log error 41 reporting: The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly.
Windows 7 Pro, HP Compaq Business Desktop dc7100 - P4 550 3.4 GHz purchase 9/29/05
4-sticks new EDGE 1GB PC3200 DDR DIMM and new 400W Antec power supply installed this week. BSOD's less frequent after this new hardware installed. Also increased BIOS idle time fan speed thinking possible CPU heat related issues. CPU heatsink visually clean but not removed for thorough cleaning.