Excel Opens EVERYTHING!
 

I've done something with Excel 2003 and I can't figure out what. I have it
loaded on this machine, but it was not in the Start/All Programs area so I
went to My Computer and navigated to the folder containing the Excel.exe
file. To make a long story short I've allowed something -- data, digital
signature...something -- to take over and now if I click on anything (and, I
mean anything!) Excel will open saying the file format is incorrect (that
happens when trying to open Outlook in the Start menu) or if I navigate to
Control Panel and click on add/remove programs Excel opens and says the
digital signature is invalid and something about a security concern. I'm
stumped. Any thoughts or suggestions besides throwing this computer out the
window? Thanks, in advance.
DBullis