Need help! Deleted my aero theme and can't see anythng now

I was playing around with 3rd party themes and installed some 3-4 themes. It was really good. But some time later i found out that my excel and word files were messed up by the glass setting (backgrounds were all black). So what i did was i went to resources/themes and deleted the folders of the themes i downloaded not being aware that aero is either being in used or is the default window theme (correct me if I'm wrong). Now my login screen is all black. What should i do? I'm trying to use sfc scannow but it says my drive is protected or smthng.

Have you already tried getting into Safe Mode with Networking and re-establishing the Aero theme?