can't open excel files from folder

[tburwinkle]

I have a number of excel files organized into various folders for different
projects. But lately when I try to open one of the files from the folder
itself, I get an error message that says the "file could not be found", to
"check the spelling of the file name", and to "verify that the file location
is correct". When I try to open the file through Excel, I get the same
message. BUT, if I drag the file to my desktop, I can open it from my desktop
without a problem.

Anyone know what's happening here? I've run my antivirus software on the
files, but they're clean.

Thanks