Hi,
As bnt says, might be worth perusing the logs.
Click on start, and type eventvwr into the search box and open up Event Viewer.
Once in there, make your life easy by filtering down as follows :
- Right click "Custom Views"
- Select "Create Custom View"
- In the "Logged" drop down, choose a suitable time range (e.g. last 7 days)
- Under "Event Level" check Critical & Warning (or even just Critical)
- Select the "By log" radio button
- In the "Event logs" drop down, check both primary options (win logs & app logs)
- Hit OK
- Give it a name
- Hit ok
- Click on the newly created view on the navbar