Hi everyone I'm trying to see if an audio card exists that works like my receiver does now. I want to connect my six speakers and sub woofer directly to my computer. If someone can help I will appreciate it thanks.

I've never seen such a gizmo, and I think you're unlikely to find one as the computer's bus cannot supply the power needed to drive standard unamplified speakers. A receiver is basically a big amplifier with a tuner and other niceties. The options are getting a discrete amp for your existing speakers, powered amplified speakers, or keeping your existing receiver in the mix.

Another possibility is finding a complete HTPC vendor that incorporates a built-in amp. Alienware used to have such a beast with their Hangar product, but their website doesn't show it anymore.

You could also incorporate an amp yourself from components (Power Amplifier Kit), packaged and shielded to fit in a PC chassis, or specialized cards (Stereo 20W Digital Audio Amplifier Card).