can someone help me????   i deleted a theme that was applied and now my desktop doesent work. what sgould i doo plz help meee!!!!!!!   sory for my english

Try alt-ctrl-delete, open task manager and see if explorer.exe is running in processes. If it is, end the process. That should force Windows to restart it, which should undo the problem.
If it is not running, click new task and start explorer.exe.