Try System Restore using the Command prompt follow these steps:
Restart your computer, and then press and hold F8 during the initial startup to start your computer in safe mode with a Command prompt.
Use the arrow keys to select the Safe mode with a Command prompt option.
If you are prompted to select an operating system, use the arrow keys to select the appropriate operating system for your computer, and then press ENTER.
Log on as an administrator or with an account that has administrator credentials.
At the command prompt, type %systemroot%\system32\restore\rstrui.exe and then press ENTER.
Follow the instructions that appear on the screen to restore your computer to a functional state. Hopefully there will be a date you can go back to.
Also read this info and try Last Known Good Configuration from the F8 menu