I had a client recently who couldn’t run .bat files. It wasn’t one of those cases where the bat file would just open in notepad, it just wouldn’t do anything. And right-clicking gave no “run as admin” option either. The registry on this PC for .bat files was completely corrupted. You can’t fix this by associating the .bat extension with cmd.exe – that will just open a DOS (yeah, I’m old) prompt.
I didn’t find a whole lot on fixing this. But Since I knew that this info is in the registry, I knew that restoring the registry for .bat files should work. I found this great site that will allow you to restore all sorts of default file associations. Check it out!
http://www.sevenforums.com/tutorials/19449-default-file-type-associations-restore.html