You don't necessarily have to get a card from an electronics store. Office supply stores which sell computers should have sound cards. I've bought sound and graphics cards from Office Depot, Office Max, and Wal-Mart. (caution: if you get it from Wal-Mart and it doesn't work, they will not give you a refund since the box has been opened. Check with other places on their return policy)
You can also call computer shops to see what sound cards they have in stock and what the prices are. Anyone who repairs computers or builds custom systems should have sound cards they can sell to you.
Installation is a very easy process. If I can do it, anyone can. Plus, it will cost a lot less than a new motherboard.
There is a wide price range but I'm guessing that you don't want to spend a lot for a card. You can get inexpensive cards which will work just fine. The sound on my motherboard died about 6 months ago. I went to Office Depot and got a Diamond Xtreme sound card for $20.95 (plus tax) which suits my needs.
If you do get a card and need help installing it, all you have to do is ask us and we will guide you through the process.
It's one of those things that once you do it you'll say "wow, that was easy".
Now, question time. Have you checked sound properties to make sure the sound is not muted?
Did you check to see if the sound drivers are installed? Right click on My Computer on your desktop. Click Manage.
When computer management opens, look to the left and click Device Manager.
Under Sound, video and game controllers does anything have a yellow triangle next to it? (I think it's a triangle shape)
Edit to add: In May you posted about a sound issue here: http://www.bleepingcomputer.com/forums/topic318497.html
Did you follow the suggestions given by MrBruce?
Edited by Queen-Evie, 10 July 2010 - 05:49 PM.