Are you playing back on the PC or outputting to a TV?
With Blu-ray playback, your hardware has to be HDCP compliant. So for your PC, that would include your video card and monitor. For TV use, that would include the video card and TV.
Also, I believe you have to be running XP w/SP3 or Vista and of course a player which supports Blu-ray. Both PowerDVD 7 & 8 should work fine.