Windows 7 Home 64 on i7 quadcore
GPU Radeon HD 6850
Blender 2.77a (any previous version is working fine).
Short description of error
It crashes every time I select Cycles rendering.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps
Just run Blender and click on Cycles Render.