What you could do to test the program is make a simple new picture in Photoshop, maybe with one or two shapes on it, and try to save it as a GIF - don't worry about the program complaining about info. being lost when you save, it'll do that for any format other than Photoshops own special one. Then restart Photoshop, and try to open that GIF you just created and see if it works. If it doesn't, I can only guess that something is wrong with Photoshop