audio system

I have an audio system which has just 2 inputs, RCA and TOSlink. I want to pair it with my pc which has an aux port. Is it worth it to go buy a converter, from analog to digital? Or should I just go Analog to Analog? - I use HQ audio files (192kbps+)

Computer: HP Pavilion P7 1126s Motherboard: AAHD3-HB Well recently an update from HP updates came up. It included a BIOS update. Normally I don't do those type of updates, try to stay off them, but this computer was getting old (2-3 years), and was slowly lacking even in speed. I gave it a...