My original 360 got the red ring of death after 5 years, so I bought a new slim. I pulled out my old hd which had all my games and stuff on it and connected it to my pc. I used software to create an image on my pc hd. Now I'm having problems getting my data back to my new slim. When I try using a pen drive, the slim formats it but then on my pc, it says it's full but nothing shows up in explorer. So I can't put anything on it to get my data to my slim. I'm sure I'm just missing something, maybe software but how can I get my data from my pc on to my new slim hd?

Search for Party Buffalo and use that. The Xbox uses a special file system that your PC doesn't recognize. Party Buffalo can, and will be able to access it, extract files from it, inject files to it, etc.