Manual File Extension Naming

[Sjbrand99]

Recently I have been having this annoying problem. Every time i re-name a file eg. movie.mp4 instead of renaming it i also have to put .mp4 in the rename? what setting has been changed? Its really annoying because if you forget then you have to retype it or it becomes an un-openable file!
PLEASE HELP TECHSPOT

 

[gmuser2006]

Through Windows Explorer go to the Tools menu and select Folder Options.

In the View tab find and check the "Hide extensions for known file types".