It sounds like one: a failed Windows update somewhere along the line, two: Corrupt IE Explorer, or three: Maleware.
I would try Microsoft system sweeper and see if it finds anything.
You will have to burn a CD and then boot from it.
Microsoft Standalone System Sweeper Beta | Microsoft Connect
If clean, you could also attack it this way provided you are not getting any error messages with the updates
How do I uninstall or remove Internet Explorer as a troubleshooting step?
How to solve Internet Explorer 8 installation problems