[DKK]

I am a school teacher who is trying to prevent pupils setting desktop items to anything other than the standard blue screen.
They are saving in appropriate pictures as screen savers.
I am using NT4 and windows 2000

[adamvjackson]

You might want to consider the use of DeepFreeze, a product which discards any/all changes made to a system upon rebooting. Volume/Educational licenses are available, too.

[Admiral LSD]

You might be able to use polices for this sort of thing but I must admit I wouldn't know the first thing about setting them up.

[David Kurtanidze]

Solution

Open Regedit.exe

Find this key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\ActiveDesktop

Create a new DWORD value (listed below)
Set the value to equal 1 to enable the restriction
or 0 to disable the restriction.

List of policies:
NoAddingComponents
NoComponents
NoChangingWallpaper
NoDeletingComponents
NoEditingComponents
NoCloseDragDropBands
NoMovingBands
NoHTMLWallPaper