do they have .jpg written at the end of them? if u cant get them to work on the PC try getting a program called image viewer or something like that, just open and close them and somehow it converts them so they work, i used to have the same problem when i was doing websites with dads old mac, they neva worked when i uploaded them but after using the program it worked fine.
email me 1 pic and ill see if i can fix the problem with photoshop