This article applies as of PRTG 20


Is there a way to disable Npcap installation during PRTG updates or installations to avoid conflicts with other applications that use packet inspection?

How to disable the installation of Npcap before updating or installing PRTG

As described in PRTG update process is unsuccessful while trying to install Npcap. What can I do?, there might be issues with the Npcap installation during an update of PRTG, causing the PRTG update or installation process to stop.

There might also be issues with existing Packet Sniffer and Packet Sniffer (Custom) sensors because of a missing winpcap.dll file. This missing .dll file can also cause further issues if the file is used in a different productive service that is running on the same probe system.

For this reason, we provide a registry key option as of PRTG 20.2.59 to disable the installation of Npcap.


Steps to take

Note: It is important that you back up your system before manipulating the Windows registry!

Take the following steps on each probe system where you want to disable the installation of Npcap before updating or installing PRTG.

  1. Open the registry editor and navigate to the following keys:
    • On a 64-bitWindows system, go to
      HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Paessler\PRTG Network Monitor\Probe\PreventNpcapInstall
    • On a 32-bitWindows system, go to
      HKEY_LOCAL_MACHINE\SOFTWARE\Paessler\PRTG Network Monitor\Probe\PreventNpcapInstall
  2. This step only applies if the DWORD value PreventNpcapInstall does not exist.
    Create a new DWORD value: In the current path, right-click and select New | DWORD Value. Name the new DWORD value PreventNpcapInstall.
  3. Change the value of PreventNpcapInstall: Right-click PreventNpcapInstall and select Modify. In the value field, enter 1. Confirm with Ok. This disables the installation of Npcap.
    To enable the installation of Npcap again, set the value of PreventNpcapInstall to 0.
  4. Restart the probe system.

Note: If you disable the installation of Npcap, you cannot use existing or set up new Packet Sniffer or Packet Sniffer (Custom) sensors anymore.


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Disclaimer:
The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.