Hello marsse3,
In "Device Manager" expand "Display Adapters", then right click on the ATI driver, then click on "Update", then choose "Browse my computer for Driver software", direct it to the folder in;
C:\AMD\Support\12-8_vista_win7_win8_64_dd_ccc_whql\Packages\Drivers\Display, or;
C:\AMD\Support\12-8_vista_win7_win8_64_dd_ccc_whql\Packages\Drivers\WDM
Yours may show something a little different and you may also get a prompt that, "the driver version you wish to install is older than the one currently installed" or something to that affect, so just install anyway.
Keep us updated
Don