In my recent experience ati has horrible driver issues. If i was you, id run gpu-z to see which driver you literally are using and make sure it is the version you had tried to update or install.

I tried to install 12.7 over driver version 12.6 but even after reboot.....gpu-z told me i was using 12.6 still......

Also too, use the ones directly from ati/amds website.....dont use the video drivers hp offers, theyre most likely outdated. ANOTHER thing you could try too..... google direct x runtime and gwt that updated too. That may help