hello i know buying games and give them to your freind to borrow is illegal but what if i buy used games is that illegal?
Not at all. In fact, I'm not so sure that just letting your friend borrow, insetead of pirate or burn, is illegal. I see nothing wrong with taking NFS:Most Wanted and installing it on both of your computers. Now granted, there will only be one disc, but it should still be legal.
Neither is illegal. You can buy used games, and many do instead of buying new and install them as well as lending them to your friend.