My computer has been rebooting itself at random. The most recent time made me angry enough to look at the event logs to see whether I could find the evil program causing the problem. There was an error on "disk3" which I determined was my 250GB Western Digital Passport drive. I decided the drive must be on its last leg.
I may have spoken too soon. I looked through my event logs again and found more warnings. They were occurring on both of my WD external drives. I started to wonder if something was up with that.
Upon further research, the warning indicates the computer could not write to the drive.
control panel/system/device manager/usb root hub (multiple instances because I have a gazillion USB devices connected via docking station)
In this dialogue, there is a power management tab with a very important checkbox:
"Allow the computer to turn off this device to save power..."
I really do not want to do this with an external hard drive... It appears this is what is causing my constant reboots. Computer keeps trying to write while drive is "asleep," and eventually it generates enough error messages that it causes an automatic reboot. I unchecked all the boxes, and we will see what happens to the reboot rate.