Video Quality Needs Improvement

[rdabate]

I'm looking to somehow improve the video quality of my videos. I have a ton of dvd rips that look great on the PC, but seem a bit fluttery when viewing through STV. My STV box has the motherboard below. It supports HDMI out to the TV. So I"m currently hooked up with that. I'm hitting a brick wall with this and I'm not sure where to go from here. Any suggestions on how to make the video quality perform better?

Gigabyte GA-73PVM-S2H
http://www.gigabyte.us/Products/Moth...e=GA-73PVM-S2H

[SWKerr]

What is the OS memory and CPU? I assume you are using the onboard graphics.

Is it only DVD rips you are trying to watch? Any capture card?

Good playback is usually a function of the the codecs used in Sage to playback the video. There are generally to kinds to setup in Sage. MPEG2 (DVD, OTA broadcast HD, most Analog capture cards), h.264 (BluRay and most other HD content)

Have you installed any external programs to playback video files. Cyberlink, Arcsoft etc.

[autoboy]

Is your resolution set up to match the native resolution of your TV? Do you have hardware acceleration turned on for your DVD codec?

[rdabate]

The HD TV supports 1080i, so I set the PC to 1080i in the nvida control panel.
OS: XP SP3
RAM: 2 Gigs
CPU: 2.20 GHz

The DVD Rips are in .avi format. those are the ones that seem like they could be better quality when viewing through STV.
I have PowerDVD installed, and have played one of the darkest avi files to test through PowerDVD and the quality doesn't seem any better. I say the darkest movies meaning "Color". Seems the most noticeable when viewing dark video.
When I have video problems, I've downloaded and installed klite (the full install). With that, I've just installed it, but did nothing with configuration.