I have a toshiba laptop with windows 7 home edition. Over the past 2 or 3 weeks, the process of windows shutting down has become slower and slower. A couple of days ago, it stopped altogether. Whenever I hit the shut down button in the start menu, it logs me off as usual, goes to the "Shutting Down..." screen, and then just freezes. The rotating progress indicator stops moving, nothing happens, and the computer doesn't shut down.
The first time this happened I left it for half an hour, nothing happened. I have to hold the power button each time to get it to turn off.
When I reboot after holding the power button like this, windows doesn't give me the usual "windows didn't shut down correctly" message, it just boots normally.
I have scanned for viruses and haven't installed any new drivers or anything I think could have caused this problem over the past few weeks it's started to happen.
What is the problem and how can I solve it?