This article applies as of PRTG 23

My WMI sensors don't work after installing Microsoft Update KB50004442. What should I do?

If you recently installed Windows Update KB50004442, you might be affected by hardening changes. Microsoft recently rolled out a patch that hardens the DCOM authentication, which can cause authentication login attempts to fail.

In our experience, the issue should be fixed if all updates are installed on the PRTG core server system as well as on the target system. Alternatively, you can follow these steps as a workaround:

1. Connect to the remote system via the WMI command-line tool:
   wmic /privileges:enable /implevel:impersonate /authlevel:pktintegrity /node:"HOSTNAME" /user:"DOMAIN\USER" /password:"PASSWORD" computersystem get totalphysicalmemory
2. Change the default authentication level in the DCOM configuration tool, as well as on the probe system:
   1. Run dcomcnfg to open the DCOM console.
   2. Open Component Services | Computers | My Computer.
   3. Right-click My Computer and choose Properties from the context menu.
   4. Open the Default Properties tab.
   5. Change Default Authentication Level to Packet Integrity. ​
      
      The change should normally be effective immediately, otherwise restart the system.
      

We hope this helped resolve the issues you had.

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• My WMI sensors don't work. What can I do?