This content is not available in your preferred language.

The content is shown in another available language. Your browser may include features that can help translate the text.

Register ActiveX Controls, ActiveX Servers, and Type Libraries

Updated Jun 6, 2023



  • LabVIEW
  • Measurement Studio

How do I manually register ActiveX controls (.ocx), ActiveX servers (.DLL and .EXE), and type libraries (.TLB) on my computer?

ActiveX controls, servers, and type libraries must be registered with the operating system before they can be called from LabVIEW. 

ActiveX Control Registration

ActiveX controls are files with an .ocx extension. These controls come in 16-bit and 32-bit forms, with 32-bit being the most common. If you have a 16-bit control, you should run regsvr instead of regsvr32. 
  1. Search for Command Prompt in the Start Menu and right click >> Run as Administrator.
  2. Enter the following in the command box: regsvr32 ”<.ocx file path>”, including quotations. 
  3.  A dialog will pop up to confirm it succeeded. 

If you get an error message after registering, it could be because the ActiveX control was previously registered incorrectly. If this is the case,
  1. Unregister it by using the following command: Regsvr32 /u “<.ocx file path>"
  2. A dialog will pop up to confirm it succeeded. 

Note: If you have a 64-bit Windows, there is a 32-bit version of Regsrv32 and a 64-bit version of Regsrv32. The 64-bit version of Regsrv is in the System32 folder, while the 32-bit version is in the SysWOW64 folder. By default, the 64-bit version of Regsrv will run.   

ActiveX Server Registration

ActiveX servers can be in the form of dynamic link libraries (.DLLs) and executables (.EXEs). 

DLL Servers
  1. Search for Command Prompt in the Start Menu and right-click >> Run as Administrator.
  2. Enter the following in the command box: regsvr32 ”<server file path>", including quotations.
To unregister, use regsvr32 /u “<server file path>”

EXE Servers
  1. Select Start >> Run.
  2. Enter the following in the command: <server file path> /RegServer 
To unregister, use <server file path> /UnregServer

Type Library Registration

Type libraries (.TLB) are binary files that contain all of the type information needed to utilize the procedures and classes in a .DLL. 
  1. Navigate to the following folder and copy the file path to the clipboard:
    Note: In some situations,  such as on newer versions of Windows, you may not have regtlibv12.exe on your system. If you do not have regtlibv12.exe on your system, you can instead use Regasm.exe.
    Note: The actual folder path may be different depending on the .NET Framework version installed on your computer. This may also be located in C:\WINDOWS\system32\URTTemp\regtlib.exe
  2. Select Start >> Run.
  3. Enter the following in the command box: C:\Windows\Microsoft.NET\Framework\v4.0.30319\regtlibv12.exe "<Full path of .TLB file>", including quotations. 

Additional Information

Visit Microsoft Support articles for further information on registering ActiveX controls. More information about Regasm.exe can also be found on Microsoft's website.