I have Windows 10 and it was working fine .

But because of  too many Apps & programs  slowing it ,  I thought of removing some clutter and deleting some programs from Control Panel's- Add / remove .... but my mistake I  have deleted some Microsoft Windows important element/file

and now after starting I see only the cursor and blank screen .

  Please help .. what do I do .. Will I have to reboot Windows 7 and then upgrade to Windows 10 ??

Previously if anything was going wrong with Windows 10  just pressing F8 would solve the issue but now even after pressing F8 nothing happens .

   Please help immediately as I am unable to surf from my Dell NetBook .

            ~ Thanks