Try IRFANVIEW and VLC Player. Maybe it's just bad luck and you lost a few.
I'm having a problem with some jpeg's, I shot 274 pictures over the weekend, most of them a fine and the computer recognize them but the final 24 pictures cant be seen. The computer says their there and the file size is 4.66 MB (4,887,490 bytes) but there's no thumbnail just a picture file image. When I try to open it the computer says (it appears that we don't support this file format) even though it's a .JPG ????