Easiest way to tell would be to simply look at the card's jack and see if the pins would line up, then carefully insert it.
It should be a standard type plug though. My 4400 uses a standard one; but my old GF2gts used an s-vid type plug, but had more pins, so wasn't compatible without a special adapter.
Note: Your TV's s-video input is "expecting" video and audio; the gf4 card only outputs video. Not a problem if you only use the TV as just a video screen. If you need the sound to go into the TV too, you'll have to find a way to combine the s-video out from the vid card and the audio out from your sound card and combine these into a standard s-video cable to go into the TV's s-video jack. I'm sure you could buy adapters and stuff, but I think the cabling will start to get messy.
If the TV also has RCA jacks, you could simply get an s-video to RCA adapter (has s-vid connector on one end and one RCA jack on the other). Route that to the video RCA jack on your TV. Then use a "headphone-plug to RCA" adapter to go from the sound card to the TV's RCA audio jacks.
Much easier to route just the s-video cable to the TV, then route the audio to a stereo receiver or simply use the PC speakers.