Connecting Sony DAV-FR1 sound system to PC

Hey guys,

So my dad is installing a new 7.1 sound system in our family room where we have our big widescreen TV and he's giving me the Sony DAV-FR1 surround sound system that he had hooked up there, replacing my older Logitech Z-680 system. I have a PC, an Xbox 360, PS3, PS2, Wii and a 28" HD monitor set up in my room, the console systems I can hook up the the receiver no problem, but the PC I can't figure out how to hook up...my sound card is a Creative X-Fi Xtreme Gamer sound card...can anybody tell me how I can hook up my PC to this sound system?