CAN'T SEE DESKTOP AFTER LOGON, ONLY BLUE BACKGROUND AFTER PROMOTE A DOMAIN CONTROLER

Hi, my name is Omar

I promoted two domain controllers yesterday with Windows Server 2008 R2. Both work fine as a domain controllers role but when I logon, I can't see desktop, I only see a blue background, I 'cant see any desktop Icon. We have already had that problem and i remember that we change a value on a registry key but i can't remeber what was exactly.

Thanks for your assistance

ovazquez