How can we prevent Users in a Citrix or Terminal Services environment from accessing the Omni Tools Login window, but still allow Powerusers access?
Security access to the Omni Login window can be set-up from GP Security. You can grant or revoke access to the Omni Login window or any window in GP, through the normal Security windows.
For GP 10, you would need to know where the access for the Omni Login window is currently granted (by default, it would be in the DEFAULTUSER Task, unless you have changed that).
Lastly, log out of GP and then log back into GP for the change to take affect.