1, we are in Win10 computer we press the keyboard Win + R combination , and then open the "Run" window, we only need to fill out the "Regedit.exe" open the registry, details as shown in the following figure:
2, in the entry to the registry we only need to locate the "Hkey_classes_root\directory\background\shell", on the shell right click, select "New---item", details as shown in the following figure:
3, now we change the name to "Notepad", and then in its name we will create a child of the command, the right window, double-click the "Default"-"Edit string" address we fill in as C:\Windows\System32\notepad.exe, click "OK", As shown in figure:
4, OK now we'll see a notepad option in the right click, as shown in figure:
5. Okay, so that's it, adding other apps is the same as long as you know it installs the directory's executable file.