Really Messed up my file associations and I can't get them back

Cheesepie

Reputable
Dec 31, 2014
5
0
4,510
So I opened something with notepad and forgot to untick "Always use the selected program to open this kind of file type" so all of my exes open with notepad.
This has happened quite a few times before so I went on the internet to find out how to do it because I had forgotten, and a site recommended that I get this program http://izt.name/apps/types/.

I started messing about on it stupidly not knowing what I was doing; to find a solution to my problem.
Went on the properties of .Exe and unticked "used linked class". Now all of my exes won't open as they don't know what to open even if I go to the directory and my desktop currently looks like this
http://imgur.com/dXgNzMo (Sorry for potato quality)

I am willing to help in what ever way I can as I am really in a mess here!
Sorry if I did anything wrong this is my first time posting