Clean and Check Discs
The Xbox 360 cannot read games that are covered in fingerprints, dirt or scratches. Inspect the unplayable disc carefully. If you see any smudges, wet a lint-free cloth with water. Gently rub the disc with the cloth to remove the smudges. You cannot remove deep scratches. If your disc has a scratch on it, a disc resurfacing company can sometimes repair it for you. Try to play the game after a cleaning or repair. If it does not play, try to play other games. If other games also do not play, the Xbox 360 may need a repair.
Clear the Xbox 360 Cache
The Xbox 360 saves updates and certain game files to its cache. Over time, these files build up and start to slow down the system in the same way that built-up files tend to slow down a computer. Cleaning the system's cache deletes these unnecessary files, allowing the Xbox 360 to read discs more efficiently. To clear the cache, scroll to "My Xbox," "System Settings" and then "Memory." Select the Xbox 360 hard drive and press "Y." Choose "Clear System Cache."
Remove Peripherals
Damaged Xbox 360 peripherals, such as USB drives, memory units or the hard drive, sometimes make games unplayable. Turn the Xbox 360 off and remove any peripherals attached to the console. To remove the hard drive, hold down the gray button on the side of the Xbox 360. Grasp the edges of the hard drive and lift it away from the system while holding down the gray button. If a game plays with these peripherals removed, replace the damaged peripheral.
Send the Xbox 360 for Repair
If the Xbox 360 cannot play games after you try multiple troubleshooting solutions, it likely has a hardware problem that only Microsoft can repair. Go to the Xbox website and navigate to the Online Service Center. Click "Start a Repair Request." Sign into your Xbox LIVE account and describe the details of the error you are experiencing. Remove any game discs and peripherals, including the hard drive, before sending the system to Microsoft's repair center.