The video feed runs from the satellite to directv box with coaxial cable. Then to PC with yellow RCA cable. Next from PC to monitor,with current setup, a VGA connector. But I will have DVI capabilites in the PC soon and the monitor has a DVI connection. So the question is, will changing from VGA to DVI too the monitor improve video quality/resolution for live TV? 

Its a 19" nice LCD monitor. Running 1280x1024 natively. Hauppage TV Tuner for input and currently on board ATI HD 3200 for output. The DVI upgrade is coming from an upcoming dedicated graphics card.

Thank you

The yellow composite video cable is bottlenecking your video quality for live TV. You need a better video feed from your Direct TV box to your computer. Do you have any other video out options from the Direct TV box?

coaxial output on the box also. i am also limited by inputs into the computer. (rca, coaxial, or s video)

Your best bet, when its time to upgrade your monitor you select one which has at lest one HDMI port. Apart from that, I dunno what you can do really.

Use coaxial then.

I'd say no. The only difference I noticed was the colour on DVI was a little more saturated but TV/TVcard settings can change that.

Ideally you want to go straight to the monitor from satellite box with VGA/DVI/HDMI.

If the satellite box isn't HD then using the TV card should improve the picture compared to yellow RCA straight to the TV. My TV card and graphics card settings definitely improved the picture.