Excel 2003 won't start. Suddenly wants to install

[iiibbb]

When I click on the shortcuts or directly on worksheet files the installer
wants to install from an original disk. My office software came
pre-installed on this machine, and I cannot find my orignial or recovery
disks due to a recent move.

When I try to run excel or excel.exe from the start menu, I get a message
that it cannot find the program. My other office software still works.

What can I do?

 

[iiibbb]

Update--

I tried "repairing" it in the add/remove programs. It sees that it's there,
but says the program isn't working properly. When I hit repair it goes into
the same reinstall routine.

I'm almost positive that I did not receive installation disks with my
computer when I bought it. The programs were pre-installed. I'd have to
wipe the whole drive, and I am not happy about that prospect.

Isn't there some other way?