Stop Opera from Auto updating

Stop Opera from Auto update. Steps:
1.Just goto the installed directory(default is C:\Program Files\Opera).
2.Open the folder with the version number of Opera(something like 15.0.1147.153 or 16.0.x.x.x).
3.Delete or rename the file named opera_auto_update.exe.
4.Restart and it won't bother you again.