How to hook up a computer to a home theater

you can get one of several outboard DACs that accept USB input with RCA out, or you can go with a high end sound card with RCA out. Based on your description of a high end HT, i would recommend the former. There are some very good new DACs that accept USB input.

This is what I use...comes with everything you need.

http://www.xitel.com/product_phfl.htm

Dave

You are confused I think on what wifi is. You certainly can use it if you wish, you just need a device like the Sonos or Squeezebox, or a USB to SPDIF converter to get the digital out of your computer. Read up on here, there are tons of threads, and if you have specific questions then post and you should get good response.