One semi-common way to bork Windows is to make all
.exe files (i.e. programs) open with some program instead of launching as programs in their own right. People apparently do this with several programs:
I believe these are all essentially the same question (just with different associations), and there are basically only two answers to it. Are these all duplicates of each other?
The best dupe target, if we were going to close them, would probably be How to repair a broken .EXE file association.