Windows 8.1 allows the user to change the file association for .bat files. I made the mistake of using this facility to change the default file association for .bat files to Notepad++. Now when I attempt to run a .bat file, the script for the .bat comes up in Notepad++, instead of its being run as an executable file!  All my .bat files are now useless.

It seems we need to change/reset some registry entry, but which one?

Thank you 

Running Windows 8.1, I set my ".bat" file association to NotePad++.
Double-clicking the file will open in NotePad++

I then deleted the following key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.bat

".bat" files now executed fine.  The icon was still NotePad++ until Explorer refreshed.

Hello Maged Salama,

Is this issue resolved?

Have you tried the suggestion as Steve Hardee mentioned?

Best regards,
Fangzhou CHEN