Youtube crashing my PC (amd driver)

Hi

I have a problem with youtube crashing my pc
It normally happens after awhile and not the first video the screen goes green/black and I get this message

Display driver stopped responding and has recovered
Display driver AMD driver stopped responding and has successfully recovered

If I try to watch another video the video is just a black screen

I can generally keep using the computer for a short time until it freezes and I need a hard restart

Also if I try to go down to restart the computer it freezes as well


my graphics card is this one
AMD Radeon HD 7450

Any ideas how to fix this?
thanks!