I've searched and although I found some info, a lot of the links are dead.

I downlaoded 1.74 for Civ IV and now I get this error message
"Error loading shader libraries"

The game had been working fine before, I want to play online and it had me download the patch.

Install latest DirectX

Do you have a link?

Try this link for DirectX (http://www.microsoft.com/downloads/details.aspx?FamilyID=2da43d38-db71-4c1b-bc6a-9b6652cd92a3&DisplayLang=en).