In order to fix the issue, go to Start, type cmd and open the application using Administrator rights. Type cd\windows, press Enter, type regedit and press again the Enter key. Locate the .exe folder in the HKEY-CLASSES-ROOT, double click the Default entry and change its value to exefile. Next, scroll down to exefile entry and go to shell > open > command, double click the Default file and enter **"%1" %*** as value. After you exit the Registry Editor, reboot your PC.
If the problem is not solved, navigate to Control Panel > Programs > Default Programs > Set Default Programs, select Notepad from the list and click Choose defaults for this program. Un-ckeck the .exe extension, click Save and restart your computer.