Hmm I'd probably open Windows safemode with command prompt, that way visuals wouldn't mess up the system and I would be able to revert any actions that would have damaged the startup screen.
Can you write me in Skype (from your phone, perhaps?), I'll tell you what to do. If not, at least try to use safe mode first and restore your Windows to the last successful boot.
I actually fixed it with system recovery.
Also i've removed the icons and themes.