Start up taking 8 hours

My Windows 7 hung itsself up this morning. I had to use the power button to restart. I chose Safe Mode. I now have the screen:

Start up repair.
Start up repair is checking your system for problems
Attemping
Might take an hour

That was 8 hours ago and it is still running.
I pressed the Cance button and got the answer "Cannot cancel"

What now? Any ideas?
Thanks
Herri

Hold down on the Power Button, or turn it off using your power plug.

If you have a Windows 7 Disk you could try booting Normally, if not run a Repair Install.