Disabling Desktop Background in RM Connect

[iking]

Anyone know a way of disabling the ability to set a Desktop Background on an RM Connect network. Pupils desktop backgrounds disappear when they log off, but they can change it once they are logged in. I can't see anything obvious in the settings for the User Types or Global Workstation Settings in the Management Console.

Is there a registry fragment which would do the job?

[webman]

I think this would depend on the user type assigned to said users. Our standard and advanced user types aren't able to change their wallpaper.

[iking]

Our standard user (unedited RM connect version) can set their desktop background using picasa, so it doesn't seem to be disabled by default.