I would recommend trying a fresh install of our latest Catalyst 15.5 Beta drivers, available from www.amd.com/beta.
Please follow this guide to uninstall your current drivers first, prior to installing (or reinstalling) 15.5 Beta.
If the same issue still exists after these steps, then the graphics card might be faulty. If this is the case i would notify the retailer you purchased it from to enquire about a refund or a replacement. Make sure to fully inform them of the steps required to replicate the fault so they can test it internally.
I have followed your steps but still get the same crash.
Is there anythin else I can do?
Thanks a lot for the answer.