To help diagnose a system (Windows 7 Pro x64) that has been rebooting by itself on what appears to be a fairly regular basis, I'm looking for a utility to keep a log of the date and time for each time it boots up. Ideally, it would also keep track of the time elapsed between successive boots.
What I'm trying to find out is whether there is a pattern in the reboots or whether they happen completely at random.