Why can't I delete the patch for Fallout New Vegas?

I went to system settings and cleared the cache but when I started up fallout NV an update notification did not appear. So I assumed it did not clear the patch but it worked for all my other games.Why can't I delete the patch for Fallout New Vegas?
From the Xbox 360 Dashboard, go to the 'system settings' and select 'memory'. From there highlight your Xbox's primary storage device, and press Y. From the next menu that appears, select 'clear system cache'. Select yes on the warning screen that appears, and you're all done!



Update: The Xbox 360 process has changed for later updates. To delete the patch, go to system setting 鈫?memory 鈫?primary storage device 鈫?games 鈫?Fallout: New Vegas, and delete "Fallout: New Vegas title update #4". When you start up the game again, you will be told that there is an update to the game. If you opt not to download it, you will be signed out of Xbox Live. Upon loading a saved games, an error message will appear stating that the game relies on content that is no longer available, with an option to back out of the saved game load.