Im using Photoshop C52 to make a skin, and I try to copy from a picture (in paint) into the skin, but it wont save. Then I tried to open the other picture in c52 but i cant find a way to copy from one to another, It just messes up the skin. Is it even possible to copy and paste in photoshop? It should be but I dont get how to.

.... ofcourse it's possible to copy and paste in photoshop. Just select what you want to copy and (to use the shortcut) press 'ctrl' + 'c' to copy and 'ctrl' + 'v' to paste, it will paste it in a new layer, wich is good for editing purposes. When you save, as default it will save as a PSD(photoshop project file) but when you select something like 24bit Targa, it automaticly merges all layers together for the save and than return to the project file. So the Saved .tga will be just like any other tga while you can still work with the PSD....
This story might be a bit confusing since I'm very bad at explaining things clearly but than again.. I didn't exactly understand what you were trying to say either .
I hope this helped you, Good luck

RC-1290'Dreadnought'

Or... you can just drag whatever you want to copy into the other picture. If you are trying to copy something from the same picture then make your selection (with the lasso tool or whatever you use) and press Ctrl J