saved game from windows 7 - vista?

Me and my mate have an fm night in eache others houses the problem is he brought our saved game over on his HD and it wouldnt transfer into my laptop, so we started a new 1 in my house and he took the new saved game home and it wouldnt transfer to his laptop. Could this be due to my Laptop running windows 7 and his Vista? Any ideas guys?

Maybe the 'saved file' is corrupted. It should be able to load regardless of the operating system