I've made this point before, but it's worth repeating: Before you purchase a network card, be sure to check the Windows XP Hardware Compatibility List (HCL). You should purchase cards that appear on the HCL or that are marked by the manufacturer certifying their compatibility with Windows XP or 2000. You can find the HCL at http://www.microsoft.com/hcl.
If your adapter was already installed when you set up Windows XP, it may already be ready to go, in which case you can skip this section and jump down to “Installing Network Wiring.” Follow these steps to see whether the adapter is already set up:
Right-click My Computer and select Manage.
Select Device Manager in the left pane, and ...