This article is, if for no other reason, something that I required to fix a crazy problem with a D-link wireless network card that basically took out this service completely from windows xp.
The basic points are listed below but if you require more information you should read the full article. As this is not something you will have to fix hopefully ever in your lifetime, this blog entry will probably be more for me when I am in the field and come across this same problem again. It is nice to know that I can visit my own blog to find the answers!
Click the Start button, and then click Control Panel. If you're in Category View, then click the Network and Internet Connections icon, then the Network Connections icon. If you're in Classic View, double-click the Network Connections icon. In the Network Connections window, under LAN or High Speed Internet, select the Local Area Connection icon. On the menu bar, click File and select Properties, or just right-click on the Local Area Connection icon and select Properties from the context menu). In the Local Area Connection Properties window, on the General tab, click the Install button. In the Select Network Component Type window, under "Click the type of network component you want to install," click to select the Service icon, then click the Add button. In the Select Network Service window, click the Have Disk button, then the Browse button. In the Locate File window, browse to the C:\Windows\Inf folder (this is a hidden folder). Click to select NETWZC.INF, then click the Open button. In the Install From Disk window, click the OK button. In the Select Network Service window, in the Network Service box, select Microsoft as the manufacturer, then click to select Wireless Zero Configuration. Click the OK button.