Saving as a .gif on Photoshop CS2 not an option

Hi, I have a question about certain file formats. When I open up Photoshop CS2 and try to save an image as a .gif or even a .png that isn't on option on the drop down menu. I only have about 10 options, most formats that are rarley ever used. I think someone my menu got screwed with and I'm wondering is there a way to reset it? Thanks so much!