Photoshop can't open/parse a file

[phillipbauer]

I received several dozen Photoshop images on a CD. When I try to open some of them, I get a message that says  "Couldn't open file. may be corrupt or an unrecognized format." OR, "Photoshop can't parse the file." I have tried re-naming the file extension to TIF and EPS but no luck.  Is there a way around this or is it a corrupt file?