Can't hide my files extentions

[Abdelrahman92]

Hello, I can't hide my files extentions even when I check
"Hide extentions for known file types" in folder option.
Every time I check it, it goes back again unchecked.
What do I do?

 

[Trevers1987]

There's a thread here about file extensions hope this of some assistance. http://www.sevenforums.com/tutorials/10570-file-extensions-hide-show.html