If you had to do a clean install of Windows 2000 and then do a full restore, or a full System State restore, a network adapter may be missing from Device Manager. A new device, like Wan miniport (L2TP) may be listed instead.
If you did NOT use the same deployment method to do the clean install as you used for the original install, you may experience this problem.
If you cannot get the NIC to install, you might try an in-place upgrade.
If the in-place upgrade doesn't solve the problem, try the following:
1. If TCP/IP is your only protocol, install an additional protocol, like NetBEUI.
2. If this computer is a domain controller, restart in Directory Services Restore mode, otherwise, restart in Safe Mode with Networking.
3. Remove the TCP/IP protocol from the Local Area Connection.
4. If this computer is a domain controller, restart in Directory Services Restore mode, otherwise, restart in Safe Mode with Networking.
5. Install the TCP/IP protocol in the Local Area Connection.
6. Remove any additional protocol that you added in step 1.
7. Restart normally.
If the above procedure does not resolve the problem:
1. Do a clean install of Windows 2000 using the same deployment method as the original install. If you originally used the CD-ROM, use the CD-ROM now. If you originally did an unattended install, do an unattended install now, using the same unattended installation script.
2. Perform the restore.