My oldest computer (specs below) has developed a problem in which, even after a clean shutdown, it will sometimes (maybe 50% of the time) restart by itself using within 10 seconds. I have always had everything in the BIOS that that might start the PC disabled (WOL, USB, etc). After the PC auto-restarts I will again press the power button to shutdown at the Windows user login screen, it will shutdown but again start back up. This is a new issue. This behavior isn't like telling Windows to "restart". The PC actually comes to a full shutdown for a few seconds (fans off, etc) and then it restarts. I've had to resort to turning off the PSU power switch after a shutdown to keep it shutdown.
Another recent issue - for the first time in a long time I needed to use the DVD drive to install a game. The drive wasn't working at all so I deleted the device from Windows Device Manager and scanned for new hardware. It found the drive and it started working. I was able to install the game successfully. However since that time that PC has been experiencing BSODs rather frequently, a few times a day. I'm not sure if this issue is related to the auto-restart so I thought I'd mention it as well.
Any ideas on either issue?
Athlon 64 X2 3800+ (1.8 Ghz Toledo core) @ default
Foxconn 6150BK8MC-KRSHN2 motherboard
Integrated Nvidia 6150 graphics
Retail AMD CPU cooler
2.0 GB DDR RAM
80 GB Western Digital SE hard drive
Fortron "Blue Storm" 500w ATX 12v 2.0 PSU
Windows 7 Home Premium 32-bit