It seems your issue is due to the installed discrete gfx card. If the gfx card is set as the primary adapter the default Media SDK samples will not work with HW acceleration.
One way to resolve this is to make the Intel GPU the primary adapter (normally via BIOS). Alternatively you can initialize the Media SDK session with the MFX_HARDWARE... target as described in the Media SDK manual appendix.
More info can be found in this forum post:http://software.intel.com/en-us/forums/showthread.php?t=86355&o=a&s=lr
I am getting this exact same issue only when using the -hw option. I have the i7-3720QM CPU @ 2.6GHz. I am running a MacBook Pro Mid-2012 with bootcamp installed and Windows 7 Ultimate x64. I installed the lastest bootcamp drivers for my machine. Any ideas?