Not sure why it is happening but today when I tried to use OpenCL on my HD4000, I kept getting a crash (Either with my app or GPU Caps Viewer OpenCL benchmarks).
I have a GTX580 in my system but for the OpenCL Tests, I am disabling it in the device managers.
I uninstalled/reinstalled the Intel Driver (old one win64_152812.exe) since it is the one working for me.
But no luck this time.
So I decided to uninstall the Nvidia driver (320) and suddenly everything was working again.
This might not be an Intel Issue but I just flag it here in case somebody else see something like that.
Laurent.