Every 23 minutes in my system event log (Win 7) I see an error with event id 6008. It tells me "the previous system shutdown... was unexpected". When I work at the computer it doesn't happen so it must be something that happens during idle time.
The event immediately before (4 minutes before) is "The WinHTTP Web Proxy... entered the stopped state". The one before that is always "The Disk Defragmenter service entered the running state." Where can I find out if this service is being told to start every 23 minutes and how can I stop it (assuming this is the culprit)?