Originally Posted by stevemedes
Okay... is the lack of H.264 decoding the reason that button is greyed out?
No. If you try and play a MPEG-2 DVD or file, the option will be enabled automatically. H.264 and WMV files will get no purevideo hardware decoding, but if you use the nstantmedia.exe player that comes with the purevideo decoder, you will still get the video filters.