1. Open RegEdit
2. Go to HKEY_CLASSES_ROOT\Folder\shell
3. Add a new Key to the "Shell" Key and name it anything you like.
4. Give it a default value that will appear when you right click a folder, i.e. NewKey (use an "&" without the quotes, in front of any character and it will allow you to use the keyboard)
5. Click on the Key HKEY_CLASSES_ROOT\Folder\shell\NewKey
6. Add a New Key named Command
7. Set the (Default) value of the application you want to run
8. For example: c:\program files\internet explorer\iexplore.exe (Include the full path and parameters if you need them)