BleepingComputer.com: I.E. 8 - stopped working

On I.E. 8 under Windows 7, suddenly Internet Explorer will not continue to work and must be closed. When each time it is opened, the message in middle of screen comes up,
"A problem caused your program to stop working. Internet Explorer will be closed down."

I do not know how to investigate this problem. I tried clearing browser history but this did not fix the problem. The internet connection is fine; that Windows 7 computer is hooked to a router directly by wire; and the router also broadcasts a wireless signal which I pick up and use the internet without any trouble on another computer (done wirelessly on it, Windows XP this wireless laptop computer); yet the Windows 7 desk-tower computer directly wired to the router will not achieve I.E. 8 staying open and working. I.E. stops and must close.

How do I investigate? What do we look for?