Video Playback Quality

I'm playing FLV, SWF and MP4 files with MS AirPlayer and playback appears to drag and is slow with all files compared to other players playing the same files on the same PC. I'm using a WINDOWS 7 PC with 3 GHZ Pentium Processor and fast graphics card. I've played 1920x2160 (Extended; 2 screens) in the past and played beautifully and smooth with no problems. Flash is latest version.  Really don't want to downsize files and lose image quality. What can I do to resolve this?

Flash supports hardware acceleration but you will need the video to be H.264 encoded and have a video cards that is on the Nvidia Flash / GPU supported list.

http://www.adobe.com/devnet/flashplayer/articles/fplayer10_1_hardware_acceleration.html