Simple good IT behavior: Don't install something you don't need. Technically, all you need in an HTPC that'll play downloaded movies (H264, VC1, MP4, matroska containers, mp4 containers), DVD, BluRay discs, is FFDShow, Haali Media Splitter and maybe QuickTime Alternative. CCCP, is a great "combo", but you're never sure how these components interact together... especially if you use a AV receiver to decode your AC3 and DTS via S/PDIF. More: IllSeeYouInHell was talking earlier about one of the greatest plugin for VMC: MediaControl. This fantastic tool is known to be broken when you combine it with CCCP or any other codec pack. I'm not a programmer neither an expert. Just a guy who wants to keep is HTPC as light as possible and understand what is installed. I'm honestly happy that CCCP works well with your (and probably most) setup. But with my experience, it was problematic (go see the MediaControl forum for examples). Also, if you go x64 like I did, you'll realize that CCCP can't help you there, you must find all the filters individually and register the DLLs manually and creat your MIME associations (except for FFDshow, that got his own x64 build). When CCCP goes x64, I promise I'll give it a try! Regards.