March 2018 Windows Update removes Virtual Network adapter

March 2018 Windows Update removes Virtual Network adapter

It seems after installing Microsoft KB4088875 on Windows 7/2008R2 you will get a new Virtual Network Adapter

A new Ethernet virtual Network Interface Card (vNIC) that has default settings may replace the previously existing vNIC, causing network issues after you apply this update. Any custom settings on the previous vNIC persist in the registry but are unused.

To fix this issue, run the VBS script that’s provided below. Copy and paste this in notepad and save with .vbs extension.

Before you run the script, make sure that you back up the following registry key and subkeys:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\PCI
Option Explicit
Const HKEY_LOCAL_MACHINE = &H80000002
Dim oReg : Set oReg = GetObject("winmgmts:{impersonationLevel=impersonate}!\\.\root\default:StdRegProv")
Dim oShell : Set oShell = CreateObject("WScript.Shell")
Dim sPath, aSub, sKey, aSubToo, sKeyToo, dwValue, Result, SaveResult
Dim NotDeleted
 
NotDeleted = 0
 
' Get all keys within sPath
sPath = "SYSTEM\CurrentControlSet\Enum\PCI"
oReg.EnumKey HKEY_LOCAL_MACHINE, sPath, aSub
 
' Loop through each key
For Each sKey In aSub
    ' Get all subkeys within the key 'sKey'
    oReg.EnumKey HKEY_LOCAL_MACHINE, sPath & "\" & sKey, aSubToo
    For Each sKeyToo In aSubToo
      Result = oReg.DeleteKey(HKEY_LOCAL_MACHINE, sPath & "\" & sKey & "\" & sKeyToo & "\" & "\Device Parameters" & "\SlotPersistentInfo")
      ' Allow failure only if key never existed
      If (Result = 1) Or (Result > 2) Then
        NotDeleted = 1
        SaveResult = Result
      End If
    Next
Next
 
If (NotDeleted > 0) Then 
  Wscript.Echo "One or more SlotPersistentInfo keys still exist under HKLM\System\CurrentControlSet\Enum\PCI\<deviceid>\<subdeviceid>\Device Parameters.  Please delete manually. Result = " & Result
End If

Note that restart of the server will be required after executing the script.

There are unofficial reports that KB4088876 having the same issue on Windows 8.1/2012R2. GPins is reporting that it’s not only the vNIC is affected:

It’s not just the vNIC that is affected.

From a conversation I just had with VMware, it apparently resets the PCI bus which winds up re-enumerating some of the virtual adapters. Some of the devices come up fine, others don’t

A couple of the systems I have, have multiple drives on multiple luns running paravirtualization interface got re-hashed as well as the NICs. As such the MS SAN policy wouldn’t let the drive come on automatically, had to go in and ‘Online’ the specific volumes in question and then rebooted to assure it stayed up. I will need to go in and disable that specific policy during my next maintenance window so if the volumes get re-hashed again I don’t have to worry about them coming online properly.

-GP

See also KB3125574 for more information.

Branko Vucinec

About Branko Vucinec

Hi! I'm Branko, a Systems Engineer focused on Microsoft technologies from the Netherlands. I enjoy helping organizations with the business and people opportunities and challenges surrounding tech.

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