I can now confirm the latest Intel driver for HD4000 IGP on Windows 8 works for H.264 copy-protected channels (using the Cox 3D channel for testing which is H.264 and copy-once confirmed via 411-info). The older HD graphics on 1st Gen Core i5 still not working (there is no new drivers for it).
I can also confirm that the Windows 8 WMC key MS given out for free last year still works even though MS claims that it must be used before 1/31/2013.
Thanks OP for pointing out that Cox 3D channel is H.264 copy-protected. In my area, it is channel 896 and its content is seasonal. Last year, it is London Olympics. Now, it is ESPN 3D.