Your gfx card is dead.
There is a high chance you need to get a new one.
Checklist:
- Check if your gfx card gets recognized in the system bios
- Reinstall Gfx-card drivers
- Reinstall DirectX
- Check all connection and plugs
Did you recently
- install/uninstall software (games, drivers, programms)?
- install/uninstall hardware?
