Error C000-0099 occurs when you try to download an update to your Xbox 360 console

You see the following error code and message when you try to download an update to your Xbox 360 console:

Can't process the update. If the problem persists, go to www.xbox.com/support.
Status Code: xxxx-xxxx-xxxx-xxxx-C000-0099

Note The “x” characters vary.

This may mean that your Xbox Live account is locked.

If your Xbox 360 console has been tampered with or modified, it can no longer connect to Xbox Live, install software updates or play new games that require a console software update. You can still play your existing games offline.

• Physically disconnect your network cable or remove your Xbox 360 Wireless Network Adaptor from the console.
• Follow these steps to turn off automatic sign-in so that you can play games offline. To turn off auto sign-in:
  1. Restart your console.
  2. Select No if you are prompted to update your console software.
  3. Press the Guide button on your controller.
  4. Go to Settings, and then select Profile.
  5. Select Sign-in Preferences.
  6. Set Profile Auto Sign-in to “Off”.
  7. Press the B button on your controller to return to the Xbox Dashboard.

Your console can now play your existing games offline only. However, any future attempts to sign in to Xbox Live or update your console software will result in an error.