Wal~mart employee here....
We exchange everything same for same, doesn't make a difference if you have a receipt or not. We can not return opened software or anything of the sort because Wal~mart will get fined for every piece that does get returned. You can very easily get fired for returning things of this nature and they can look everything up to see who did, etc.
If I exchange software or anything with a customer who complains it has a problem, I open the new product in the store before they leave so they can see it has no visual problems. This also serves another very important reason, they can not return the newly exchanged item to get their money back as it has been opened by me. Wal~mart will take back itemes without a receipt so this is why I do this. People get really mad and give me all the dirty looks they have but I don't care as I'm not about to let someone screw over Wal~mart on a product that does not have a very high markup to begin with. I did this very thing for a customer with windows XP. His girlfriend claimed he was a computer genius, blah, blah, blah. He was pretty much computer illiterate if you ask me but he had enough brains to figure out how to make a nice little back up cd for his use. I gave them a new copy of XP but they were still mad at me, oh well!!
~Amdskip