PRB: "Unexpected error; quitting" Installing VB4 Application

When you attempt to install a Visual Basic 4.0 32-bit application created using the Setup Wizard, the following error message appears:

This problem occurs because the target machine has version 5.x of Olepro32.dll installed but does not have version 2.20.xxx of Oleaut32.dll installed. This can happen when Visual Basic 4.0 developers install an Office 97 application, Internet Explorer 3.0, or Visual Basic 5.0 on their machine (thus installing Olepro32.dll version 5.x), and then create a distribution using the Visual Basic 4.0 Setup Toolkit. The Visual Basic 4.0 Setup Toolkit includes version 5.x Olepro32.dll in the files it installs. When an attempt is made to install the Visual Basic 4.0 application on a machine that does not have the version 2.20 Oleaut32.dll, it fails as described above, leaving the updated version of Olepro32.dll on the target machine.

Also, any application on the target machine that uses Olepro32.dll will no longer work because Olepro32.dll attempts to forward calls into the new Oleaut32.dll, which is not present.

The Visual Basic 4.0 Setup Toolkit cannot be used to install the updated Oleaut32.dll on the target system because doing so requires the system to be restarted and the Visual Basic 4.0 Setup Toolkit does not have this capability.

To correct problems on target machines where installation was attempted, there are two options:

1. Install an application that includes the new Oleaut32.dll onto the problem machines by installing any of the following apps: Internet Explorer 3.0 or Visual Basic 5.0 CC edition (downloadable from the Web), Office 97, Visual Basic 5.0, Windows 2000, Windows NT 4.0, or Windows NT 3.51 Service Pack 5.
2. Get the original Olepro32.dll from the Visual Basic 4.0 operating system CD-ROM and replace the 5.x version of Olepro32.dll with it. Machines that are not having problems do not need to delete any files.

You now need to recreate your installation so the problem will not re-occur. Do this by copying the following components from the \vb\system directory of your Visual Basic 4.0 CD-ROM:

to the following folder:

Now recreate your distribution. Microsoft Visual Basic 4.0's Setup Wizard always looks first at the above folder when searching for dependent files. When you install your application, only less-recent files on the target machine will be overwritten.

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.