How do you move your xbox gamer profile to a computer and back?

I was wondering how you can move your gamer profile to a computer and back to the 360, just in case something happens to the original and a back-up is needed.|||You don't need to make a back-up. Your Xbox 360 gamertag and profile is always saved by Microsoft. All you do is recover your gamertag if you lose it on your 360 and there you go. The only way to lose your gamertag is to have your Xbox Live inactive for 6 months.