It's not a dumb question
, wish more would ask such before installing new components.
A new motherboard has drivers for various functions...sound, video, NIC, etc.
Sometimes XP already has the drivers for these in it's cache...in some cases, it will install these when XP is installed. Sometimes users must use the auto-install routine available on drivers CDs, sometimes the drivers will have to be installed by going through Device Manager.
The easy way to ensure all drivers are properly installed...is to go to Device Manager (Start/Run...type devmgmt.msc and hit Enter) and review the status displayed for all components. If you see a yellow question mark, that indicates that a driver needs to be installed or that something is wrong with the installed driver.
If something is wrong with the installed driver, there are a few tricks to removing such...and then trying to install that driver again.
I find this useful at such times, How to uninstall hidden devices, drivers, and services - Tech-Recipes.com - http://www.tech-recipes.com/windows_instal...on_tips504.html