Help me with my xbox 360 ?

The gamer-tag is only meant to be on one hard-drive at a time. I recover mine round a m8s house for the time i spend there, and they do the same here. but once they recover it round onto their hard drive again i cant sign in with their account on my xbox. If you want my advice i would just say bring your hard drive with you from house to house. The gamer tag is on the hard drive so when you plug it into the xbox round a different house its just like having you're xbox there. You can remove the hard drive by pressing the little grey button to the front of the console on the front of the hard drive. unless you want to get a new Gamer tag on the xbox round your dads house because then you would be playing one for each console but wouldn't have the same achievements and you would be paint double. Apart from that there is no solution.