A20 Hardware Error Installing Windows 3.0 on AST Premium (74636)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 5.0a

This article was previously published under Q74636


The Microsoft Windows version 3.0 Setup program may hang on disk #2 when you install Windows under Microsoft MS-DOS version 5.0 on an AST Premium 80386 machine when the message "A20 Hardware Error" is displayed on the screen.


If this error occurs, check the CONFIG.SYS file for the line "DOS=high." If it exists, change it to "DOS=low", and remove any third-party device drivers such as ASTEMM.SYS. Reboot the machine to have the change take effect.

Begin the Windows Setup program again.

Modification Type: Major Last Reviewed: 9/30/2003
Keywords: KB74636