Fixing Unregistered .OCX Files in Running Legacy Application on Windows 10 (64-b...

Introduction

I obtained a legacy copy of software written in 2002 without any documents. When I run it on Windows 10, it gives me two error messages:

Component  'MSCMCT2.OCX' or one of its dependencies not 
correctly registered: a file is missing or invalid.

Component 'COMDLG32.OCX' or one of its dependencies 
not correctly registered: a file is missing or invalid

So how do we make this legacy app to run on Windows 10? I did some research on the internet and figured it out from this reference[1]. By going through all these steps, I sucessfully run this leacy app. I summarized these steps and wrapped into a short tip to save you time in the future for the same scenario.

Also, this tip is for me to save these reference links for future use.

Following reference [1], I installed and registered these two components. It works well and this legacy app fired up.

Background

These kinds of OCX components are ActiveX controls and are used in old/classic Visual Basic applications. They are responsible for functionalities same as the common controls in Windows Form in .NET.

Download these OCX Components and Register Them

Step 1 Follow reference [2] to download Microsoft Visual Basic 6.0 Service Pack 6 Security Rollup Update package.

Step 2 Then use 7-Zip to extract it into a local folder

Step 3 then copy MSCMCT2.OCX and COMDLG32.OCX into C:\Windows\SysWOW64

Step 4 Run command prompt in Administrative Previlidge.

Step 5 For Windows 64-bit systems: regsvr32 C:\Windows\SysWOW64\COMDLG32.OCX For Windows 32-bit systems: regsvr32 C:\Windows\System32\COMDLG32.OCX if this component is successfuly registered, we will see this message:

DllRegisterServer in comdlg32.ocx succeeded.

Points of Interest

I posted my question in Lounge and got one comment from Amarnath S for Dependecy Walker. This tool is useful for complicated cases. For my small app, I only went through two steps and resolved the issues.

Reference

History

2022-05-06 initialized this file.