Windows 7 – Unable to Join Domain with Professional Edition

Generally, a standard part of a domain setup includes the disabling of this ability. Fast user switching is primarily used for home computers and your domain administrators, rather than using a Group Policy settings, simply remove the system service to prevent work arounds.

I have not seen a managed domain that allowed fast user switching.

You can use Run As for many tasks that require elevated permissions. Some installations will fail when you do this, but many others will work.

I'd talk to the IT group and ask if this is what they've done.

I was able to get around by going to this location in the registry:

HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System

Inside, there's a key called Wallpaper. I deleted it and re-set the desktop background, and it worked.

You'll have to do that every time you log on though, as group policy refreshes itself. (It can also be set to refresh automatically.)