The only other thing I can think of is that maybe your File Types aren't Registered.
To check this, open Windows Explorer, (This might vary slightly depending on which Version of Windows you are using). From the Menu select Tools->> Folder Options, Select the File Types Tab, scroll down to see if BMP, JPG, JPEG etc are Listed. If they are, then that's not the problem. If they're not, come out of Folder Options, while in Windows Explorer find a .bmp file, double-click on it. You should get a Popup "Open With" Window, select Paint. For .jpg, .jpeg etc repeat the previous instructions, but select your Graphics Package as the "Open With". This procedure will Register your File Types and you will, if this was the problem, have to re-insert your Images in your App.
I'm out of suggestions now.
Good Luck
Bill