WMV high definition system playback

[lokus]

I was wondering if anyone has a successful setup for playing back WMV High defiintion files to their television? I don't know if anyone is using Windows Media Center edition or running films through S-video to their displays. I only have one HDMI port on my TV which is being used for my PS3. I have an S-video connection on the back of my TV with audio ports, as well component high definition inputs. What type of system could I setup that will allow playback of high def files to my TV? I'm not looking to spend an extreme amount of money (i.e. build a new HTPC or buy an Xbox360). My initial idea was to run s-video and audio from my PC (AMD AM2 6000+ with 2gb of ram and a video card capable of supporting blu-ray/hddvd playback) to my television. My only concern was my ability to get the 720p or 1080p high definition video quality from this configuration. Any ideas?