Hi, thanks for your reply! This unfortunately did not work but deleting sniffer_gpu.exe did the job!
I would not call that a correct answer.
Deleting things from your Photoshop installation area is not a good idea. It may break your ability to get updates in the future.
And Pictus 171, no, it's still only 3 keys needed: Press and hold Control - Shift - Alt simultaneously (or Command - Shift - Option if on a Mac) immediately upon cold-starting Photoshop. If you get the keys down quickly enough - and you have to be really quick - it will prompt you to confirm deletion of your current preferences, which will lead to the establishment of a fresh default set. If it does not prompt you, you haven't been quick enough to get the keys down.
That means that your video card driver is the problem. If you think you have the current driver, then you may need to contact AMD to help them determine why the driver is not working correctly on your system.