block access to windows desktop

[webmast3r]

hi everyone,

i am creating a sort of virtual desktop, and i already have blocked all access to everything... i also simulated the task bar...
the user has only access to some icons (internet explorer, irc, ..., some games, office applications,...)
i have blocked all windows shortcuts, alt+tab, ctrl+esc, i also blocked all the options from the ctrl+alt+del window...

the only problem that i still have is: when a user types "dektop" in the internet explorer address bar, the windows explorer will open, showing the windows desktop... how can i prevent this operation? (same goes for control panel and my computer)

i appreciate any help and suggestions
thanks

Dany