This article applies as of PRTG 22

Fix the malfunction of WMI (Windows Management Instrumentation) sensors. Related to WMI configuration or installation, in which important WMI components are missing or were not properly implemented.

Going through the list below can help fix the problem. We also recommend that you read the following article for general information about WMI:

• Windows Management Instrumentation: Frequently Asked Questions

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Troubleshooting list for WMI sensors

Make sure that:

• DCOM is enabled on the probe system and the target system. Check the respective registry entry.
• The user whose credentials are specified for monitoring WMI is a member of the Domain Administrators group in the same Active Directory as the target system. If a target system is outside of a domain, the user must be a member of the local Administrators group and of the DCOM group and of the Performance Monitoring group on this system.
• The monitoring user’s access rights on COM and WMI include remote access rights for the target system. Read about Securing a Remote WMI Connection.
• The target system's Windows Firewall is set to allow WMI. Windows XP and Windows Server 2003 users should read this article: Connecting to WMI remotely with VBScript. For systems with Windows Vista and later Windows versions, read this article: Connecting to WMI on a Remote Computer.
• If the firewall is enabled by group policies, you also enable the "Allow Remote Administration Exception" as outlined in this article: Group Policy: Windows Firewall setting to allow your WMI scripts to run.
• The RPC server that is used for WMI on the target system is running on the port that is specified in PRTG (135 by default).
• DCOM and RPC have open high ports in the 49152-65535 range on Windows Vista and Windows Server 2008 or later. In previous Windows versions, ports in the 1024-5000 range are required. Some users have found that opening TCP port 1091 helped them to get a connection. For more information, read this article  Service overview and network port requirements for Windows.
  To define a more specific port range for DCOM, follow these steps:
  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 Protocols tab.
  5. Open the Properties... of Connection-oriented TCP/IP.
  6. Define the port range you want DCOM to listen on. Set a minimum of 100 ports in the 49152-65535 or 1024-5000 range, depending on the Windows versions in your environment.
• Security software: It is always a good idea to double-check that no local security software (anti-spy, antivirus, and others) on either side is blocking WMI connections.
• If you do not get a WMI connection, try to restart the WMI service manually or change the IP address of the target system to its DNS name in the device settings in PRTG. This establishes a completely new WMI connection, which might help.

Troubleshooting in detail

Refer to the following articles for further information:

• Are there any testing tools for WMI?
• What are the most common errors when monitoring WMI?
• My WMI sensors show errors with a PE code. What does that mean?
• Which WQL queries are used by the PRTG WMI sensors?
• Why do my WMI sensors show error PE263 after updating PRTG?
• Why do I receive the sensor error message 'Connection could not be established (code: PE015)'?

Here is another good article about troubleshooting WMI:

• WMI Troubleshooting Tips

Tips against slowness on Vista and Windows 2008:

• WMI on Vista or Windows 2008 is painfully slow. What can I do?

If you are monitoring a massive number of hosts with one probe, the following article might help. Keep in mind, however, that it is always a good idea to distribute WMI queries over one or more remote probes.

• Memory and Handle Quotas in the WMI Provider Service

If you are experiencing high handle count in WMI service (Winmgmt) or WMI provider (wmiprvse.exe), read this article:

• WMI: How to Troubleshoot WMI High Handle Count

PRTG settings for WMI

PRTG offers a few settings for dealing with WMI issues:

• What are the "WMI Compatibility Options"?

Tips and tricks

The following articles provide guidelines for special scenarios:

• How can I monitor WMI sensors if the target machine is not part of a domain?
• WMI consumes a large amount of memory on my Windows Server 2008 R2 – what can I do?

How to repair WMI

If none of the proposed solutions work, we have gathered some procedures that might fix the WMI system on affected computers:

• I have tried a lot of things to fix my WMI. What else can I try to avoid reinstalling Windows?

More

Another good article about all issues regarding WMI can be found under:

• WMI Reference This reference provides a list of WMI providers, information on the COM API for WMI, WMI queries, WMI log files, WMI security, WMI tools, and WMI infrastructure objects and values.

Further articles of interest, which provide more detail than the troubleshooting articles above, and which relate to particular aspects of WMI configuration can be found under:

• Connecting to WMI on a Remote Computer
• Creating a Connection to a WMI Namespace
• WMI Error Constants
• WMI Classes

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.