Black screen

What settings did you change? If you can remember what those changes were then you can go into Windows in safe-mode and change those settings back. If you can't remember then when you go into Windows in safe-mode you will have to do a system restore to the day before you made those changes.
On a lot of bois chips safe mode is f-8 and it may say it on the bottom of the screen when booting through the bios.