.sfv files' icon change
 

I recently (accidentally) changed the icon on all of my .sfv files. It used to be a nice green tick, but now it's a miniature icon of the "Easy SFV Creator" program. Is there any way I can get the tick back?

You should right mouse click on one of them and pick properties. Then change software that is default for this kind of files and pick the one you want to use. If it will not help just reinstall software you want to use for it.