I got this very same error message and I tried almost everything listed here. I finally figured out a fix: check your hardware acceleration if you are getting the black screen on all videos - well Real Player and Quicktime are fine, but I could not play a DVD, nor did Media Center even have a DVD option any longer. That fixed it all. Go to control panel, display, settings, advanced and then troubleshooting. My hardware acceleration was turned off - knew how it happened but didn't know how to fix it (long boring story). This worked like magic and I only stumbled across it because I downloaded a new program for my video card that finally gave me an error message that was useful. Hope this helps...