My .exe icons are corrupted

I was using Internet Explorer to access dictionary.com when suddenly the browser shut down and  most of my .exe icons on my quick launch, Start Menu, and All Programs lists started showing the default Windows icon.  

Some of the icons, like for IE, when clicked bring up a "Open With" dialog.  If I click "ok" it tries to download an iexplore.exe instead of open the browser.

I clicked on Notepad from my Start Menu, same "Open With" dialog, and then after I selected NotePad from the list, it opened a text file of gibberish, not a blank text file.

Also, I tried to open MS Word from the All Programs menu and got the error dialog "Application not found".

Any ideas?

(P.S. I am new to EE, so I hope my points offer is sound).