People are generally universally disappointed when they figure out just how limited most TV sets are compared to monitors. Adding some insult to injury, the better quality your TV set, the more pronounced this difference is.
The other problem comes about in that, unless something has changed recently, Windows can't do any sort of dual monitor type setup over TV-Out. Also, XP can't have two monitors running at different resolutions last I checked. So given that S-Video is limited to about 1024x768, even if the other problem didn't exist, you'd be forced to run your monitor at 1024x768.
However, since you have those two limitations, what would happen is along the following. You can only have a display on your monitor OR your TV, not both. If you run a higher resolution than 1024x768, if you switch to using the TV, you will automatically be switched to 1024x768, and icons on your desktop will get all shuffled around. Creating a second user account solely for the use of watching things on your TV will not work either, since Windows doesn't support different users having different resolutions.
What I've found to work really well, believe it or not, is a Microsoft Xbox (the original, not the 360). You can pick one of these up off ebay used, and then either install a modchip into it, or what's known as a softmod. These let you replace the internal hard drive with a larger one, and run the excellent "homebrew" program Xbox Media Center. The great thing about the Xbox is that it already has the necessary hookups for a TV. Composite, S-Video, and Component video are all supported, and composite and toslink audio are also supported. Add in the DVD kit, which includes a remote, and you're good to go. Icing on the cake is the built-in network port, which you can use to stream files from your PC or just load them onto the Xbox's internal hard drive. It will fit nicely into most entertainment center slots for VCR or DVD players, it's relatively quiet, and will be ready to use in less than 30 seconds from pressing the power button.
The only drawback is that the Xbox just doesn't have the power to play back a lot of video files in high resolutions. So you won't be able to play back many files at 720p or 1080i if you have a nice HDTV capable of these resolutions. For standard resolutions though, it works surprisingly well.
That would be what I recommend you do. It's probably the most versatile and flexible solution I've come across. There are packaged solutions out there, but none of them stack up quite as well. What you have now is likely never going to live up to your expectations, no matter how low they are, so I'd suggest just taking it back now.
I am operating windows XP and I have a GeForce 6600 GT graphics card.
I have just bought a wireless system to transmit my PC picture to my TV. The system plugs into the S-video port on my graphics card and everything looks to be plugged in correctly, but there aren't any instructions about how I set up the PC to get it to redirect the picture to my TV via the wireless set up through the S-video port.
Can anyone help?