Twice when I tried to shut windows down it wouldn't respond. On my machine it has to check the A drive before it will shut down.

Both times it didn't check the A drive and
then wouldn't shut down. It didn't make the noise it makes when it checks the A drive.

Also, I recently defragged. I didn't have any program running before I tried shut down except the solitaire game.

What can I do to fix this problem?

Do I have to uninstall and reinstall windows?

And if I do then do I have to back up all my files?

Or is there some other fix for this?

I checked HELP on my computer and it didn't
list any problem like this.