Can I Fix My Xbox-360 Game?

i just recently got Grand theft auto IV (#5) from a friend, and after playing my xbox acted up and now it has a visible circle going all the way around it. i tried using both windex and toothpaste to fix it and it did work for about 4 levels but now a message comes up saying disc is unreadable so i have to turn the xbox off…..is there anyway i can fix this? if you can tell me any household items i could use like toothpaste or windex THANKS..

Suggestion:

if you go to gamestop u can buy game fixing stuff and it only costs 5 to 9 bucks thats ur best bet