Windows 3.0 Doesn't Run in 386 Enhanced Mode (96830)


The information in this article applies to:
    • Microsoft MS-DOS operating system 5.0
    • Microsoft MS-DOS operating system 5.0a
    • Microsoft MS-DOS operating system 6.0
    • Microsoft MS-DOS operating system 6.2
    • Microsoft MS-DOS operating system 6.21
    • Microsoft Windows 3.0
    • Microsoft Windows 3.0a
This article was previously published under Q96830

SUMMARY

This article discusses how to correct the problem of Microsoft Windows version 3.0 not running in 386 enhanced mode on a system with Microsoft MS-DOS version 5.0 and later.

The article is divided into the following subsections:
    • Extended Memory Requirements
    • CONFIG.SYS File Requirements
    • AUTOEXEC.BAT File Requirements
    • WINA20.386 File Requirements
    • Additional Steps for Systems Running EMM386.EXE

MORE INFORMATION

To ensure the Microsoft Windows version 3.0 can run on your system, make sure your system meets all the requirements discussed in the following subsections.

Extended Memory Requirements

Your system must have at least 1 megabyte (MB) (1,048,576 bytes) of extended memory. To determine the amount of available extended memory, type the following at the MS-DOS command prompt, and press ENTER:

mem

If you do not have 1 MB of available extended memory, reduce your system's extended memory usage by removing the DOS=HIGH command from your CONFIG.SYS file. If you are using the version of SMARTDrive that is provided with MS-DOS 5.0 (SMARTDRV.SYS), reduce the value of the MinCacheSize parameter. If you are using the version of SMARTDrive that is provided with MS-DOS version 6.0 or later (SMARTDRV.EXE), reduce the value of the WinCacheSize parameter.

CONFIG.SYS File Requirements

By default, Setup configures MS-DOS to install HIMEM.SYS when you start your system. If MS-DOS does not install HIMEM.SYS, make sure the the following command appears in your CONFIG.SYS file before any commands that start device drivers or programs that use extended memory:

device=c:\dos\himem.sys

In addition, verify the following in your CONFIG.SYS file:
    • The FILES command must specify at least 30 files.
    • The BUFFERS command must specify at least 20 buffers.

AUTOEXEC.BAT File Requirements

Your AUTOEXEC.BAT file must include a SET command such as the following that establishes the location where temporary files are stored:

set temp=<drive>:\<directory>

where <drive> is your hard disk drive and <directory> is the directory where your temporary files are stored. This set command creates an environment variable that Windows version 3.0 uses to determine where to store its temporary files. For example, the following command directs Windows to store its temporary files in a directory named TEMP on drive C:

set temp=c:\temp

WINA20.386 File Requirements

Your system must include the WINA20.386 file. The Setup program for MS-DOS places this file in the root directory of your startup drive (usually drive C). If you have moved the WINA20.386 file to another directory, you need to edit your CONFIG.SYS and SYSTEM.INI files to reflect the accurate location of this file. Use the procedures outlined below.

If you can't find the WINA20.386 file in any directory on your hard disk drive, expand and copy the file from your MS-DOS installation disks to the root directory of your startup drive by typing the following at the MS-DOS command prompt and pressing ENTER

expand <floppy>:\wina20.38_ <startupdrive>:\wina20.386

where <floppy> is the floppy disk drive that contains the installation disk with the compressed file you want to expand, and <startupdrive> is your startup drive. For example, if your installation disk is in floppy disk drive A and your startup drive is drive C, type the following command:

expand a:\wina20.38_ c:\wina20.386

The WINA20.386 file is located on the following installation disks: 
    MS-DOS       3.5-Inch Disk  5.25-Inch    3.5-Inch   5.25-Inch
    Version      Number (1.44   Disk Number  Disk       Disk
                 MB)            (1.2 MB)     Number     Number
                                             (720K)     (360K)
    -------------------------------------------------------------

    MS-DOS 5     N/A            N/A          Disk 3     Disk 5
    Upgrade
    MS-DOS 5.0a  N/A            Disk 2       Disk 3     Disk 5
    Upgrade
    MS-DOS 6.0   Disk 1         Disk 2       Disk 3     Disk 5
    Upgrade
    MS-DOS 6.2   Disk 1         Disk 2       Disk 3     Disk 5
    Upgrade
    MS-DOS 6.21  Disk 1         Disk 2       Disk 3     Disk 5
    Upgrade
If you have moved your WINA20.386 file to a directory other than the root directory of your startup drive, use the following procedure to allow Windows 3.0 to find it:

    • Edit your CONFIG.SYS file. To edit the file using MS-DOS Editor, type the following at the MS-DOS command prompt and press ENTER:

    edit <startupdrive>:\config.sys


    • Add the following line at the end of your CONFIG.SYS file:

    switches=/w


    • Save your CONFIG.SYS file. If you're using MS-DOS Editor, choose Exit from the File menu. When MS-DOS Editor displays a dialog box prompting you to save your file, choose the Yes button or press ENTER.
    • Next, use MS-DOS Editor to open your Windows SYSTEM.INI file. Your SYSTEM.INI file is in the directory where your Windows files reside. To edit the file, type the following at the MS-DOS command prompt and then press ENTER:

    edit <drive>:\<directory>\system.ini

    where <drive> is your hard disk drive and <directory> is the directory where your Windows files reside. For example, if your hard disk drive is drive C and your Windows files are located in the WINDOWS directory, type the following command:

    edit c:\windows\system.ini


    • Locate the section of your SYSTEM.INI file that begins with the [386Enh] heading, and add the following command:

    device=<drive>:\<directory>\wina20.386

    where <drive> is your hard disk drive and <directory> is the directory where the WINA20.386 file is now located. For example, if you moved the file to your WINDOWS directory, you would add the following command to yourWindows SYSTEM.INI file:

    device=c:\windows\wina20.386


    o  Save your SYSTEM.INI file. If you're using MS-DOS Editor, choose Exit from the File menu. When MS-DOS Editor displays a dialog box prompting you to save your file, choose the Yes button or press ENTER.
    • Restart your computer by pressing CTRL+ALT+DEL.

Additional Steps for Systems Running EMM386.EXE

If Windows version 3.0 doesn't run in 386 enhanced mode after you have checked the items listed above, and you are using EMM386.EXE, do the following:

    • Use a text editor, such as MS-DOS Editor, to open the SYSTEM.INI file that is located in the directory where your Windows files reside. If you want to use MS-DOS Editor, type the following at the MS-DOS command prompt and press ENTER

    edit <drive>:\<directory>\system.ini

    where <drive> is your hard disk drive and <directory> is the directory where your Windows files reside. For example, if your hard disk drive is drive C and your Windows files are located in the WINDOWS directory, type the following command:

    edit c:\windows\system.ini


    • Insert the following command in the [386Enh] section of the SYSTEM.INI file:

    EMMEXCLUDE=A000-EFFF


    • Save your SYSTEM.INI file. If you're using MS-DOS Editor, choose Exit from the File menu. When MS-DOS Editor displays a dialog box prompting you to save your file, choose the Yes button or press ENTER.
    • Start Windows version 3.0. If Windows version 3.0 does not run in 386 enhanced mode, a device conflict is preventing Windows from running in 386 enhanced mode. Call Microsoft Product Support Services for help.
Modification Type: Major Last Reviewed: 11/26/2003
Keywords: KB96830
©2003 Microsoft Corporation. All rights reserved.