WIN.COM Is Required to Upgrade Windows 3.0 to 3.1 (83745)

SUMMARY

If you upgrade a Windows 3.0 installation to Windows 3.1, and WIN.COM has been renamed to something else, Windows 3.1 Setup will not perform an upgrade, but will install on top of Windows 3.0. You will be left with a nonfunctional setup, and may receive one or more of the following error messages:

Cannot find a device that may be needed to run Windows in 386 enhanced mode. You need to run the Setup program again.
Invalid VxD dynamic link call to device number xxxx, service yyyy. Your Windows configuration is invalid. Run the Windows Setup program again to correct this problem. To continue running Windows, press Y or ENTER. To quit the current program, press N. If you continue running Windows, your system may become unstable. Do you want to continue?

MORE INFORMATION

Windows 3.1 Setup looks for WIN.COM to determine if there is a current installation of Windows 3.0 or Windows 3.1. If Setup finds a Windows 3.0 WIN.COM, it will perform an upgrade, keeping the Windows 3.0 configuration, while adding the Windows 3.1 files and settings.

If no WIN.COM is found, Windows 3.1 will perform a standard installation over the top of a Windows 3.0 installation. Windows will not function correctly if this is done.

If you have renamed WIN.COM to something else, and the Windows 3.1 Setup fails, the following works around the problem:

Rename WINVER.EXE to WIN.COM. This has the result of removing the Windows 3.1 WINVER.EXE file, and creating a dummy WIN.COM.
Rerun Windows 3.1 Setup. Setup will not find WINVER.EXE and will find WIN.COM. Setup should complete normally.

NOTE: If the above procedure is not followed and Windows 3.1 is installed again, the Windows 3.1 WINVER.EXE file will cause Windows 3.1 Setup to improperly install the Windows 3.1 files and settings, and will not update your printer drivers.