Problem with Excel's .lnk and file association

I had a user who accidently installed an application directly to the
root of \program files. Walked through a Wise uninstall, said "No to
all" for .DLLs in system folders, and uninstalled, then reinstalled to
its own subfolder.

Now when he tries to open Excel from the desktop, the start menu, or
the program group, he gets a dialog box with the message, "The
installation source for this product is not available. Verify the
source exists and that you can access it". A couple of odd things.

1. A shortcut direct to excel.exe works fine.
2. The file associations are broken too. The icons are correct but
the same error occurs on clicking. Tried reassociating direct to
excel.exe with no luck.
3. Word and Power point are fine.
4. The only thing Excel specific in the reinstalled application is
they provide an .XLA. But, there were no issues before the
reinstallation.

Any ideas?

Thanks,

Curtis