I am unable to install TCP/IP, why?

A. If you are trying to reinstall TCP/IP after previously uninstalling it the problem may be due to certain TCP/IP registry values not being removed correctly.

To manually remove perform the following:

1. Start the registry editor (regedt32.exe)
2. Select the key you want to delete.
3. Select the 'Security' menu and select 'Owner...'. (The 'Owner' dialog box appears.)
   Click 'Take Ownership'.
4. Select the 'Security' menu and select 'Permissions...'. (The 'Registry Key Permissions' dialog box appears.)
5. In the 'Name' list box, select 'Everyone'.
6. Select 'Full Control' from the 'Type of Access' drop-down list box.
7. Select the 'Replace Permission on Existing Subkeys' check box.
8. Click 'OK'.
9. Repeat steps 2 to 8 for all registry keys to be deleted
10. Reboot the computer so that Registry changes are recognized by Windows NT.

An alternative which avoids having to change security is to start regedt32.exe under the System account by submitting it via the schedule service

C:\> net start schedule (only if not already running)
C:\> at <time> /inter regedt32.exe
C:\> net stop schedule (only if you had to start it)

Once the computer has rebooted restart REGEDT32.EXE and ensure all of the following are deleted (these are the keys whose security you must set)

Connectivity Utilities:

• HKEY_LOCAL_MACHINE\Software\Microsoft\NetBT
• HKEY_LOCAL_MACHINE\Software\Microsoft\Tcpip
• HKEY_LOCAL_MACHINE\Software\Microsoft\TcpipCU
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DHCP
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Lmhosts
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\'NetDriver'x\Parameters\Tcpip (where 'x' is the number of the network adapter).
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NetBT
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip

SNMP Service:

• HKEY_LOCAL_MACHINE\Software\Microsoft\RFC1156Agent
• HKEY_LOCAL_MACHINE\Software\Microsoft\SNMP
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SNMP

TCP/IP Network Printing Support:

• HKEY_LOCAL_MACHINE\Software\Microsoft\LPDSVC
• HKEY_LOCAL_MACHINE\Software\Microsoft\TcpPrint
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LPDSVC

FTP Server Service:

• HKEY_LOCAL_MACHINE\Software\Microsoft\FTPSVC
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\FTPSVC

Simple TCP/IP Services:

• HKEY_LOCAL_MACHINE\Software\Microsoft\SimpTcp
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SimpTcp

DHCP Server Service:

• HKEY_LOCAL_MACHINE\Software\Microsoft\DhcpMibAgent
• HKEY_LOCAL_MACHINE\Software\Microsoft\DhcpServer
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\DhcpServer

WINS Server Service:

• HKEY_LOCAL_MACHINE\Software\Microsoft\Wins HKEY_LOCAL_MACHINE\Software\Microsoft\WinsMibAgent
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Wins

Windows sockets:

• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Winsock
• HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Winsock2

It may also be necessary to remove the following keys:

• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\Root\Legacy_DHCP
• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\Root\Legacy_Lmhosts
• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\Root\Legacy_LPDSVC
• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\Root\Legacy_NetBT
• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\Root\Legacy_TCPIP
• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanManServer\Linkage\Bind
• HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanManWorkstation\Linkage\Bind

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