The file association for .BAT files needs to corrected.
This setting is user profile specific and may be corrected via the Registry.
This is the entry to delete:
Hkey_Current_User\Software\Microsoft\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.bat
After the reboot check your file associations again. It should now show:
Name =.bat, Description=Windows Batch File, Current Default=Unknown application.
With this association your bat files should execute normally.
