theres several ways to wire a pc to a home theatre amp,
best of all is to fit a dolby digital/dts (or hd versions if you have/want a 7.1 ch system) card to your pc with an optical output, same way you would if wiring a dvd player.
another is to take the original soundcards output, many of which were switchable to give you 5.1 channel output via the ext spkr/headphone output,mike input and line in sockets (blue pink green) although you would need a theatre amp with an analogue 5.1 ch input (many older and some top end amps have this input)
another way would be to run the pc's headphone/ext speaker via a 3.5mm to 2 phono plug adaptor and just connect it to the amps stereo inputs,from there you could run pseudo surround sound like dolby pro logic. just be carefull you don't overdrive the amps input by having the pc's sound set too high, set the amp for normal sound level, and adjust pc volume from low until you get adequate volume with no distortion, distortion is a warning your over driving the amp, the cure is obvious.
coupled with a 40 inch plus screen with a pc input (or even better hdmi if your pc is hdmi capable), and a decent home theater amp with good speakers, your pc becomes a jukebox/video library.
i personally use my media pc through a 40 inch sony lcd, a jvc rx6001 amp (an old faithfull workhorse) and a set of mission m34,m3ds,m3c2 and m3as, sounds sweet as a nut, f@ck i can even plug mp3's players via the telly,pc or ps3 usb sockets and get decent sound from them too (taking into account they are ripped at a high bit rate)
another bonus is install mame ((multi arcade machine emulator) in your pc and you also have the biggest 80/90's amusement arcade in your living room, add a few modern games consoles and your kids need a good slap if they come out with the i'm bored shit.
i used to dream of shit like that while i was banging two bob (10p) coins in those arcade machines in the 80's, call of duty/ assasins creed may well be buzzing, but nothing beats moon cresta.
