Error Code 145 - ActiveX Control Not Registered in LabWindows™/CVI™

Updated Apr 17, 2023

Reported In


  • LabWindows/CVI


Microsoft Office
Microsoft Form

Issue Details

Why do I get error code -145 in LabWindows™/CVI?

Error -145: ActiveX controller not registered in this computer


You get this error code when a DLL is not found for a Microsoft Form control used in a LabWindows/CVI panel. Any one of the following solutions can be used. In the first solution you should manually register the DLL, and in the second solution the DLL will be registered when you download the ActiveX Control Pad from Microsoft's website.

Solution 1:
  1. You must make sure the client computers have the same operating system as the server
  2. While creating the distribution kit, make sure you check both the Install Active X Container Support and Register files as ActiveX servers
  3. Make sure the client computer has the necessary DLL file. i.e. the DLL file for the specific ActiveX control. For example, if you use Microsoft Forms 2.0 scroll bars then make sure the FM20.DLL is present on the client computer. If not, the specific DLL file must be copied to the client computer.
  4. After copying the file to the client computer, you must manually register the DLL file as described in How Do I Register ActiveX Controls, ActiveX Servers, and Type Libraries?
Solution 2:

FM20.DLL is a Microsoft Form ActiveX component that is registered only when Microsoft Office is installed. If a Microsoft Forms control is used in a CVI panel, then registration of this DLL is needed. This is further explained on the Microsoft Support webpage.

The DLL can be registered by downloading Microsoft's ActiveX Control Pad and installing this application on the target computer. This registers the FM20.DLL component without the need to install Microsoft Office.

You can download the Microsoft ActiveX Control Pad from Microsoft's support website.

Additional Information

If you are getting this error after a Windows update you can try the following suggestions:

1. You try to repair the software by uninstalling or repair the software in Windows
2. if the step 1 doesn't work you can try to fix this error by force reinstalling LabWindows™/CVI™ in all version until the 2017 one.