My company uses the Kodicom system and we have our own private GUI for it. The site program was designed this way specifically to keep users from installing third party software on it or trying to use it for net surfing / game playing , etc.
Frankly, the only thing I can see to do is to shut down the program. This has it's own set of problems as the watchdog reset will reboot the system after a minute or two if the program is not running.
What I do is jump into MSconfig and disable the site program from running on startup. Then I reboot the machine and the watchdog will not be running. This allows me to do what I want on the machine, re-enable the site program on startup, and then restart the system.
Next time I speak with Kodicom I'll ask them if they can add a selection in the setups that will allow access to the desktop. They've been pretty responsive in the past to our suggestions.
Robert