Why does the TCP/IP protocol fail to be added?

The operating systems of several servers in our organization are NT4.0, such as database servers and Web servers. Not long ago, when I changed the network card, I accidentally deleted the TCP/IP protocol. This is not a big mistake. Just add the TCP/IP protocol, but this time I am not lucky, when the TCP/IP protocol is added, the message "Services subitem already exists" is displayed. An error occurred while adding the TCP/IP protocol! I think there must be something wrong with the system when deleting the TCP/IP protocol, and some sub-items in the Registry are not deleted. So I tried again on another NT4.0 server. I first found HEY_LOCAL_MACHINE \ System \ CurrentControlSet \ Services in the Registry and recorded all the following subitems, delete the TCP/IP protocol, open the registry, and find that DHCP, LmHOSTS, NetBT, and Tcpip are missing under Services. After the TCP/IP protocol is added, the four subitems are available again.

So I checked the registry on the server that failed to add the TCP/IP protocol and found that there are still two sub-items under Services: DHCP and LmHOSTS, no wonder the system will prompt "Services subitem already exists". After I manually delete these two items in the registry, add the TCP/IP protocol again, and the result is successful. For other Windows operating systems, such as Windows 2000 server and Windows XP, you can use this method for reference if you encounter similar problems when adding TCP/IP protocols.

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