HP Pavillion Dv7 Radeon 6770m not appearing under drivers.

[mousse]

I booted up DOTA 2 today, and all of a sudden I noticed that some of my textures were messed up. Usually, my computer runs the game on maximum with 70+ FPS, but today it ran on and under 30 FPS. I checked my device manager and I found that the graphics card had disappeared. I don't know what happened or how to fix it... Any help would be greatly appreciated.

 

[vishnu39]

when your laptop boots up ,pls check whether any details of you gpu is shown