After Update, PC Shuts Down on OS Load, Restarts, Repeats

I need help on fixing a problem with my Win 7 desktop, that is clear for a person that knows very little about Win 7 and can not make frequent visits to the PC. I am laid up in bed with a fractured ankle, post surgery where a plate and screws were installed. Thankfully, I have this laptop, crutches, and wheel chair.

Last night, my wife shut down the PC. She noticed it was installing an update. I started the PC this morning and all was normal until the screen flashed "Loading Microsoft Operating System" or something to that effect. Immediately after that flashed (for less than a second), the system powers off. A few seconds later, the power comes back on, the fans start, the BIOS screen appears, all like normal, and then shut down again. This will continue forever it appears, given I watched it repeat 4 times.

What happened? How do I fix?

Thank you.

Phil

Your wife shut it off in mid-stream, while Windows was doing an update, rather than letting it finish the update??

Can you boot into safe mode? And then run a System Restore to a day or two ago?

Do you have a Windows 7 install disk?

No, the wife did not shut it down while installing an update. She clicked "Shut Down", and noticed computer said on screen, "Installing Update". She left it, and it shut itself down after update was done.

How do I get into Safe Mode, and what would I do once there?
I have the Windows disc, but will need wife to find it.

- Phil

Safe Mode
System Restore

You may need to run System Restore from System Recovery Options.

If this fails run Startup Repair a few times, report back what it finds.