I had this problem with PowerDVD 7.3 and managed to find out what the problem was for me.
The creators of PowerDVD only added support for Intel graphics in later versions. The data for this is stored in two files called DxRenderV.dll and DxRenderX.dll that are present in the PowerDVD folder and have been for many versions of their software (though the precise folder that they're in has changed between versions).
These files are updated between versions with new graphics chip info, and I think you'll find that the ones from the current trial version of PowerDVD contain Intel support.
(Of course, the older, unsupported versions of PowerDVD also don't include the latest AACS key updates (copy protection stuff), but that's a very different problem.)