No desktop icons or taskbar

On a member server on our domain running Nt 4.0 Server SP6a, I have no desktop icons. Taskmanager says explorer.exe is running at 99/100 percent. All logins are fine. When I kill explorer the system behaves normal but still no desktop. Permissions are set to everyone full control on the %system% folder. Reinstalled service pack and security updates but not affect. Any clues?