The issue you have described could be caused by a driver or a faulty GPU. Please try the steps below to see if it resolves the issue.
1. Run the Windows self check tool to check scan and automatically repair any corrupt files found in Windows. There is a guide on how to do it here. What you need to do is run an elevated command prompt (elevated means run it as administrator) and type SFC /SCANNOW. This will generate a statement indicating if errors were found the Operating system and if they were fixable.
3. Update Windows. Install all available critical, recommended and optional updates. Often Netframework and Visual C are included in the recommended or optional updates Windows provides. Windows should always be fully up to date before installing our drivers!
4. Use DDU to sweep the system of AMD drivers.
5. Attempt to install the latest Catalyst 15.11.1 Beta drivers once the above is completed.
I've done that and the errors still happen. I really don't know what's happening, I use the PC in FULL HD with the standard drivers that came with the Windows and I can use for almost everything, except DirectX Based things. It's just Install the AMD drivers(don't matter what version) and the screen turns black for ever.
A comment that I've forgotten is: The PC keeps on but without Image, just a black powered screen(It's still sending some process because the image doesn't turn off entirely, it's like when the pc is on a Black resting screen)
It's possible to be the HDMI conector(from the video-card, not the cable) that is wrecked? I'll try use a VGA-Cable to test but this sound crazy to me.