JSI Tip 2400. 'Access Is Denied' when upgrading to Windows NT 4.0, Enterprise Edition?

When you run Winntup.exe to upgrade to Windows NT 4.0, Enterprise Edition, you receive an Access Is Denied error?

Setup found a newer version of Msvbm50.dll installed on your computer, marked with a Read Only attribute.

Remove the Read Only attribute and run Winntup.exe again.

NOTE: The file is located at %SystemRoot%\System32.