Hi Nurmi
yer updated Bios via usb no luck still
Is you PSU able to handle the upgrade in cards? it could be something as simple as your GPU simply requiring more power cause of some wierd setting in the new drivers. Else id advice restarting in safe mode, and go uninstall the driver, and remember to check the "remove files" or what ever it says check box when you do it in the drivers management section, and dont forget to go uninstall the AMD drivers program as well in your programs and features section. After that is done try reinstalling the whole thing from fresh.
And yes AMD drivers are a mean mistress at times.