server: Don't touch the users count when a system process switches desktops.

server/winstation.c

@@ -309,17 +309,18 @@ void set_process_default_desktop( struct process *process, struct desktop *deskt
     LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
         if (!thread->desktop) thread->desktop = handle;
 
-    desktop->users++;
-    if (desktop->close_timeout)
+    if (!process->is_system)
     {
-        remove_timeout_user( desktop->close_timeout );
-        desktop->close_timeout = NULL;
-    }
-    if (old_desktop)
-    {
-        old_desktop->users--;
-        release_object( old_desktop );
+        desktop->users++;
+        if (desktop->close_timeout)
+        {
+            remove_timeout_user( desktop->close_timeout );
+            desktop->close_timeout = NULL;
+        }
+        if (old_desktop) old_desktop->users--;
     }
+
+    if (old_desktop) release_object( old_desktop );
 }
 
 /* connect a process to its window station */