computer from church not playing sound at home

I have an e machine dell dimension that was used at our church thru the cound system. When I put my daughters switched on school house on it it said sound device not working. When I looked for the volume control it says there are no active mixer devices. I got speakers altec lansing from a friend but still have no sound. What driver or mixer do I need and where can I get it without it costing me lots.Help please school started today and she can't hear her lessons.

thanks

New info:

 I was able to download a driver and then fix the problem . thanks alot