Help!(releated to file types)

[Jason1]

I downloaded pics from my digital camera to my computer, and then I put them in a folder on my desktop. I can now get into that folder and open the pictures whenever I want, or so I could for awhile. When I booted up my computer the next morning, I found that all the picture files from my digital camera that I put in the folder are now some kind of script file. Why is this? I never changed them, and now if I open them I get a bunch of crap. If I try to re-name the file type with like jpg at the end, if I try to open it I get that little box with the x in it. So if somebody would please tell me how to get these pictures back to viewable form, and so thay stay like that.