Scenario: you upgrade VMware tools on one of your VMs and your IP address will not maintain a static configuration. It reverts back to a Microsoft APIPA address (169.254.0.1 – 169.254.255.254). It’s Sunday at 9:00 PM, the outage window is closing and now you are angry.

Solution: you have to clean out all references to current and previous NICs in the registry. This post tells you how to do this for Windows 2008R2 x64. Make sure you have a local administrator account and know the password before you start. You don’t want to lock yourself out of the VM should something go haywire.

Note: Make sure your VM hardware is set to a version compatible with your version of vSphere. For this post, I’m set to version 9 (for 5.1 U1c). You can run into issues related to buggy hardware mismatches.

1) Remove the NIC and reboot the VM.
a) Right-click the VM > Edit Settings > select the NIC and click Remove > OK.

2) Delete the Interfaces and Adapters from the Registry.
a) Click Start > Run and enter regedt32 and press enter.
b) Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters\Interfaces
c) Expand Interfaces and delete all entries (delete folders from the left pane).
d) Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters\Adapters
e) Expand Adapters and delete all entries (delete folders from the left pane).
f) Close the registry editor and reboot the VM.

3) Add the VMXNET3 NIC back to the VM.
a) Right-click the VM > Edit Settings > click Add > select Ethernet Adapter and click Next.
b) On the Network Connection page, select the VMXNET3 adapter type, select the network you want to connect to and most importantly, DESELECT connect at power on, and then click Next > Finish > OK.
c) Reboot the VM. Don’t skip this reboot.

4) Configure your IP address.
a) Login to the VM. Click Start > Control Panel > Network and Internet > Network and Sharing Center > Change Adapter Setting.
b) Right-click the NIC > Properties > select IPv4 and click Properties.
c) Enter your IP, mask, gateway, dns and click OK > OK.
d) Right-click the VM > Edit Settings > select the NIC and in the upper right, click both Connect at power on and Connected, then click OK.
e) The NIC will connect and you should have a clean network configuration.
f) Open a cmd prompt and enter ipconfig -all to verify. Ping other hosts to test.