There are some mixed up terms on this thread, I think he got it backwards.
coax composite = all audio and video through a single wire converted to a tv broadcast, usually fed through the cable input via a switch box.... 480i/576i or less and a horrible picture
rca Composite = all video through a single yellow rca cable. 480i/576i and a blurry picture
s-video = luma and chroma are sent separately, still typically 480i/576i. If a computer video card claims to output a higher resolution it's simply rendering in that resolution and down-sampling to the interlaced resolutions in many cases
rca component = red, blue and luma all have separate rca connections. Practically, but not quite rgb quality. Can output 480p and HD resolutions.
svga = analog rgb, no max resolution
hdmi/dvi = digital rgb, hd quality
The reason you are having trouble reading windows isn't necessarily the sharpness but the 480i limitation. Interlaced is really two 320x240 frames kludged together, which tends to make text on a computer look like crap. The only way to make it look better is to either dramatically increase the size of the font, or try to get windows running at 320x240. Both solutions have their drawbacks. The only way to make windows look decent is to use a connection that'll support 480p or higher. It's the main reason most of my cabinets now have either a svga crt or a hdmi monitor.