Will adding a "DVI out" video card to my computer make the picture on my 50' HD LCD TV sharper?

I have my computer hooked up to my TV so I can watch MPG's and other computer formatted files on the big screen. At present, I have a N-vidia 128 MB AGP8x video card with VGA and S-video out. The computer is hooked to TV using S-video cable. I have a wireless keyboard and mouse so I can sit on the couch and use the computer. When watching Downloaded movies and such on the big screen, everything is fine. But....when I try to check e mail, etc., the picture is a little blurry and Text is difficult to read. Will replacing my computer's video card to one with 128 MB AGP "DVI out" and DVI cord(my TV has "DVI in") make the TV picture as sharp as that on my 17" computer monitor? More specific, will the text and e mails suddenly appear on the 50" big screen just as sharp as they do on my traditional 17" flat screen computer monitor? BTW....my motherboard does not have PCI express slot and does not appear to be able to handle a 256 MB AGP video card. My TV is capable of 1080 dpi HD.|||Component video will give you the best picture, but DVI is better than S-Video in terms of quality.|||If your TV supports 1920x1080 through the DVI, you'll have a very nice picture. Although, it might seem a little dark or blurry at such a large size. Also, interlaced displays don't handle text quite as well, so don't get your hopes too high. Before running out and buying a new video card, make sure your TV will support that resolution through the DVI interface.