Hi Mike,
as you mentioned, allowing other user accounts for Remotedesktop session is not intended, but it is possible.
I have done this one time several month ago, let me see, if I can recapitulate the steps:
(I have only a German version of WHS running, so the translation back may not be exactly.)
- Logon to the desktop of your WHS as Administrator.
- In Start Menu, right click My Computer and select Manage.
- Navigate to Local users and Groups/Users.
- Select the user account you want to allow Remotedesktop access and double click on it.
- Click on Member tab and verify, if the account is member of Remotedesktop users.
- If he is not, add him to that group. He should also have a complex enough password.
- Now click Start/Run and type gpedit.msc.
- Navigate to Computer Configuration / Windows Settings / Security Settings / Local Policies / User Rights and double click Log on through Terminal Services.
- Add the User account to the list.
- Click OK, close group policy editor and try.
Best greetings from Germany
Olaf