FULL CONTROL + REMOVE GUEST ACCOUNT ON WINDOWS

First things first, go into your Registry by clicking the Start button, click Run and type:-
Regedit
and then ckick -OK-.
Make your way here:-
HKEY_LOCAL_MACHINE\SAM\SAM
To go beyond SAM you have to give yourself permission by right-clicking the second SAM Key, choose Permissions... highlight the Administrator and click the Full Control box, click Apply and -OK-, then close and re-open Regedit.

If that doesn't work, try this:-
Highlight the second SAM Key, right-click it and choose -Permissions...-.
Highlight the user (Administrators) and then click the Advanced button, highlight Administrators again then click the Edit... button.
Place a tick in Full Control-, click -Apply and OK-, then -OK then close and re-open Regedit to get to the extra sections.


Then make your way here in the Registry:-
HKEY_LOCAL_MACHINE\SAM\SAM\Domains\Account\Users\0 00001F5

Click the Users Folder and than click the + by the Names Folder and right click Guest and Delete. Now you've removed the guest account.