If your talking about cod 4 I just bought a used one for 10.00

Nope that would not be possible. You can buy a used copy for like $10 at gamestop, its not that expensive.

What I did, was my dad had a copy of the same game as me which wasn't working on his xbox (Mw2), so he installed my working copy to his xbox and put HIS Mw2 Disc in, therefore, because my good copy was loaded on his xbox, his bad copy only used all the information from my good copy. So my good copy was running but the disc was still required for the xbox to run the game.
Hope I helped mate. I know I didn't answer your main question very well, but I was just explaining how it works ;)

no!!!! just buy a used one for like 10 bucks

These posts... oh my god.

Find a place to rent the game, rent it for like one day. Install that disc to your harddrive. Return THAT SAME DISC back to the place got it from.

Don't try to return your scratched disc... other people want to use it too and you're just ruining it for them.

As long as your scratched disc can be read, it'll play it from the harddrive anyway.

Just buy a used copy, it only cost like 10 dollars because the game is old.

That definitely wont work, but you could probably buy it on demand or from gamestop.

RisqiiModdingTeam wrote What I did, was my dad had a copy of the same game as me which wasn't working on his xbox (Mw2), so he installed my working copy to his xbox and put HIS Mw2 Disc in, therefore, because my good copy was loaded on his xbox, his bad copy only used all the information from my good copy. So my good copy was running but the disc was still required for the xbox to run the game.
Hope I helped mate. I know I didn't answer your main question very well, but I was just explaining how it works ;)

Im sorry but did you read his post?

Use toothpaste and for some reason worked for my Waw Cod

that never worked for me.^