:( Im gonna cry!

Okay so i posted a few posts back about wanting a graphics program that i could use. Then i downloaded the gimp..and it messed up my computer so i removed it, and now all my picture files are picture files anymore! This might sound complicated so i'll try to explain better...
Before they were in Jpfg or whatever its called. Now they are just "files". The picture is still there, but i cant open it at all. Has anyone had this problem? Or know how to fix it? Any advice at all could help, i hope i didnt totally fry it and mess it up!
Sry if this is confusing i hope someone gets it...
Thanks so much
-Michelle