After you install Windows XP Service Pack 3 (SP3), the Authentication tab is missing in the properties dialog box of the computer's wired network adapter. For example, when you open the Local Area Connection Properties dialog box of a wired network adapter, you see only the General tab.
Note The Local Area Connection placeholder represents the name of the connection.
In Windows XP Service Pack 2 (SP2), both the wired and wireless connections are handled by the Wireless Zero Configuration service (WZCSVC), and this service is always running. As part of Network Access Protection (NAP) integration in Windows XP SP3, this WZCSVC functionality is divided into two separate services:
The Wired AutoConfig service (DOT3SVC)
The WZCSVC in Windows XP SP3 manages only the wireless connections. The DOT3SVC manages the wired connections, and it displays the Authentication tab in the properties dialog box of the wired network adapter. However, in Windows XP SP3, the startup type of the DOT3SVC is configured as manual. Therefore, the Authentication tab is missing until you manually start the DOT3SVC.
To resolve this issue, manually start the Wired AutoConfig service (DOT3SVC). To do this, follow these steps:
Click Start, and then click Run.
Type services.msc in the Open box, and then press ENTER.
Locate the Wired AutoConfig service, right-click it, and then click Start.