I’m unfortunately the appointed technical support person in my family and whilst it pains me to fix broken hardware, borfed OS installs or “I didn’t do anything” situations I found myself once again with a Windows XP (I know, but it works!) machine that would not get an IP address.  Troubleshooting starts:

  1. No malware,
  2. AV was installed and up to date
  3. Firewall installed
  4. Not full of unknown software or add-ons to browsers
    at this point I think the machine is in a good state and something has happens to the OS
  5. Installed a new LAN driver from the manufacturer, no change
  6. Installed and enabled the WIFI driver (wasn’t installed originally), no change.
    actually at this stage I could see my wireless network but attempting to join it with my valid key only half connected, the UI said not connected but only showed the disconnect button!

Thinking there must be something wrong with the networking / networking subsystems I searched out several options for re-installing the networking components of Windows XP or TCP/IP.

I found this from Hublerb – Tech Support Guy it’s labled hardcore method when nothing else is working but as I sounded straight forward and I could go to a back I started working through it and it worked!  I had no issues in Step #2 reinstalling TCP/IP, just added it back in a restarted.

Step #1

1. Locate the Nettcpip.inf file in %winroot%\inf, and then open the file in Notepad.
2. Locate the [MS_TCPIP.PrimaryInstall] section.
3. Edit the Characteristics = 0xa0 entry and replace 0xa0 with 0x80.
4. Save the file, and then exit Notepad.
5. In Control Panel, double-click Network Connections, right-click Local Area Connection, and then select Properties.
6. On the General tab, click Install, select Protocol, and then click Add.
7. In the Select Network Protocols window, click Have Disk.
8. In the Copy manufacturer’s files from: text box, type c:\windows\inf, and then click OK.
9. Select Internet Protocol (TCP/IP), and then click OK.
Note This step will return you to the Local Area Connection Properties screen, but now the Uninstall button is available.
10. Select Internet Protocol (TCP/IP), click Uninstall, and then click Yes.
11. Restart

Succesfull un-installation of TCP/IP will remove numerous keys from the registry including:


These represent various interconnected and interdependant services.

For good measure you should delete the following keys before reinstalling TCP/IP in step #2:


Step #2

Reinstall of TCP/IP

Following the above substep #3, replace the 0x80 back to 0xa0, this will eliminate the related “unsigned driver” error that was encountered during the uninstallation phase.

Return to “local area connection”> properties > general tab > install > Protocol > TCP/IP

You may receive an “Extended Error” failure upon trying to reinstall the TCP/IP, this is related to the installer sub-system conflicting with the security database status.

To check the integrity of the security database
esentutl /g c:\windows\security\Database\secedit.sdb

There may be a message saying database is out of date
First try the recovery option
esentutl /r c:\windows\security\Database\secedit.sdb

If this don’t work for you, you needthe repair option
esentutl /p c:\windows\security\Database\secedit.sdb

Rerun the /g option to ensure that integrity is good and database is up to date.

Now return to the “local area network setup”
Choose install > protocol > TCP/IP and try again