Your display settings is set to PAL 50, please change the display settings to PAL 60

If once you turn on the console and try to play any game but you get this message " Your Xbox 360 is set to PAL 50 please change your display settings to PAL 60 " .
You just need to check your display settings and it would differ if you have a normal TV or HD TV.

If you are using Normal TV , follow these steps:
1- Go on the dashboard to System.
2- Select Console Settings.
3- Then select Display.
4- Then select PAL settings.
5- Now select PAL 60.
6- Finally Confirm these settings.

If you are using HD TV , follow these steps:
1- Turn off the Xbox 360 console.
2- On the AV cable , set the switch to TV not HDTV.
3- Turn on the Xbox 360.
4- Go on the dashborad to System.
5- Select Console Settings.
6- Then select Display.
7- Then select PAL settings.
8- Now select PAL 60.
9- Confirm these settings.
10- Turn off the console.
Now reset the switch to HDTV.
Now put the game in the disc tray , Oh ! it's working.........

NOTE make sure the game you are trying to play is a PAL 60 game and the TV itself supports PAL 60.