What is opcenum.exe?

The .exe extension on a filename indicates an executable file. Executable files may, in some cases, harm your computer. Therefore, please read below to decide for yourself whether the opcenum.exe on your computer is a Trojan that you should remove, or whether it is a file belonging to the Windows operating system or to a trusted application.

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Opcenum.exe file information

Windows Task Manager with opcenum
Opcenum.exe process in Windows Task Manager

The process known as OPC Server Enumerator (version 1.10) or OpcEnum Module or OPC Discovery Service Executable belongs to software OPC Server Enumerator or OpcEnum Module or OPC Discovery Service or RSLinx Classic (version 2.56.00 CPR 9) by OPC Foundation (

Description: Opcenum.exe is not essential for the Windows OS and causes relatively few problems. Opcenum.exe is located in the C:\Windows\System32 folder or sometimes in a subfolder of C:\Windows. Known file sizes on Windows 10/8/7/XP are 98,304 bytes (37% of all occurrences), 60,416 bytes and 4 more variants. 
The program has no visible window. Opcenum.exe is not a Windows system file. Therefore the technical security rating is 36% dangerous, however you should also read the user reviews.

Uninstalling this variant: In case of problems with opcenum.exe, you may also uninstall the program using the Control Panel ⇒ Uninstall a ProgramRSLinx or RSLinx Classic 2.56.00 CPR 9.

Recommended: Identify opcenum.exe related errors

Important: Some malware disguises itself as opcenum.exe, particularly when not located in the C:\Windows\System32 folder. Therefore, you should check the opcenum.exe process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.


User Comments

This is used in OPC communications (Ole for Process control) and is enabled or required by many SCADA packages. It is an inter computer communications driver so unless you are playing with scada software it should not be running.
This file is required by OPC Servers/Clients to list down the OPC servers installed on a computer. This file is harmless and deleting it will cause communication errors in OPC and SCADA softwares.
  Shikhar   (further information)
office source engine
the OPC Enumerator is a browser for local or remote OPC server applications. It replaces the older method of browsing the registry directly (including by remote users) which was a possible security risk. The OPC Foundation has distributed several versions of the OPC Enum, and some vendors have produced "custom" versions that are limited to their own branded products.
Made by OPC Foundation. Part of resdistributable packages included in most SCADA software. Allows browsing of OPC client-server nodes in plantwide factory automation architectures.
  Michel A. Levesque, PEng.   (further information)
Driver installed by Rockwell Software (Allen Bradly) for their RsLinx communication drivers. Used for connecting PC to industrial controllers like PLC's or other equipment.
  Lonnie R. West   (further information)
opcenum.exe is the file which provide an interface into the local host Component Category Manager that can be accessed by remote OPC clients over DCOM.
It is essential for OPC data transfer communication to list down the Active servers in a remote machine on a network or domain
  Abhishek Bansh Prasad  
Not essential for windows but is essential for any kind of computer controlled presses, like Minster, used in manufacturing.
OPCEnum should not be deleted in any case, because it's the root process to enumerate OPC Servers installed on the local system. Without this application, it may not be possibly any more to access OPC/DCOM Servers with an OPC Client.
  Michael Schmitt  

Rating chart

Summary: Average user rating of opcenum.exe: based on 10 votes with 10 user comments. 6 users think opcenum.exe is essential for Windows or an installed application. 3 users think it's probably harmless. One user thinks it's neither essential nor dangerous. 3 users don't grade opcenum.exe ("not sure about it").

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Best practices for resolving opcenum issues

A clean and tidy computer is the key requirement for avoiding problems with opcenum. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.

Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the opcenum.exe process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

opcenum.exe [all]