The "OFF-DOMAIN" option is for special cases and is not typically used. Only use this method if you've been explicitly instructed to do so.
For students: If you are off-campus, you must first connect to RDS and then follow the steps below from within the RDS session.
1) On your computer, start the "Remote Desktop Connection" application, or mstsc.exe.
2) In the "Computer" box, enter the computer's hostname that was provided to you.
3) The authentication prompt will try to use your local Windows user credentials by default, but this won't work.
a) Click "More choices"
b) Click "Use a different account"
c) In the username field, type or paste the username you were provided with a preceding backslash "\" as pictured below.
d) Click 'OK'.
4) You should now see the desktop of the remote computer. If you encounter an error please submit a ticket to iSchool Tech Services and attach a screenshot of the error.