Is there anyway to connect my surround sound to my PC as well as my TV using some sort of audio switch box?
Then that is not "true" surround sound. True surround sound either needs 6 analog connections (5.1) or a digital connection (optical/coaxial). If you want to have sound coming from your TV and your speakers, there are a number of possibilities. First that comes to mind is... Does your TV have AV out? If it does you could simply plug the PC into the TV and connect the red/white stereo cables to your sound system from your TV. Or... Most PC's have 2 outputs. One is for headphones and the other for audio out. I don't think there will be any problem using both at once. Use the headphone out to your TV and use the audio out to your sound system.
So your PC has a sound card that outputs analog 5.1 sound? That means you have separate connections for 1) Front left/right, 2) Center/sub-woofer, 3) Surround left/right... If that's what you have simply connect those up to your surround sound system. Use a 3.5mm stereo jack to 2 RCA cable to connect from your headphone port to your TV. Then you will have 5.1 sound coming out of your sound system and stereo coming from your TV. IMPORTANT NOTE: The nature of 5.1 sound is to provide a cinema like environment through 6 independent channels. If you have your TV playing stereo sound at the same time that will muffle or confuse the sound you are hearing from your sound system. The stereo sound will have all 6 channels downmixed into 2 channels.