Windows Err Msg: Unable to Start Enhanced Mode...Back Fill (87269)


The information in this article applies to:

  • Microsoft Windows 3.0
  • Microsoft Windows 3.1
  • Microsoft Windows 3.11
This article was previously published under Q87269

SYMPTOMS

The following error message is displayed when you try to start Windows in 386 enhanced mode:
EMM386: Unable to start Enhanced Mode Windows due to base memory back fill

CAUSE

This message appears if either of the following conditions is true:

  • Your memory manager is configured to back fill base memory.

    -or-
  • Conventional memory is improperly set in the CMOS settings; that is, conventional memory is set to 512 kilobytes (K) instead of 640K.

RESOLUTION

To correct this problem, reconfigure your CMOS settings or disable base memory back fill.

MORE INFORMATION

On systems with CGA or Hercules video cards, the A000-AFFF memory range is available for base memory back fill or as upper memory blocks. If the memory is used to back fill base memory, the MEM and CHKDSK commands generally report more than 640K conventional memory available. 386 enhanced mode is not compatible with base memory back fill.

When using EMM386.EXE, consider the following:

  • Do not include the A000-AFFF memory range by removing the I=A000-AFFF statement on the EMM386 device line in the CONFIG.SYS file. EMM386.EXE does not use the A000 range by default.

    -or-
  • Include only A0FF-AFFF and use it with the NOEMS or RAM switch to load devices high with MS-DOS version 5.0 or later. For example:

    DEVICE=C:\WINDOWS\EMM386.EXE NOEMS I=A0FF-AFFF

    -or-
  • Run Windows 3.1 in standard mode by typing win /s at the MS-DOS command prompt.

OTHER MEMORY MANAGERS

386MAX

If you use 386MAX by Qualitas to back fill base memory, the following error message is displayed:
386MAX VxD Error: NOLOW option required. 386MAX VxD not loaded. Windows initialization terminated. Press any key to return to DOS.
To eliminate this problem, edit the 386MAX.PRO file in the 386MAX directory and add the line NOLOW. This includes the A000 range as upper memory address space as opposed to back filling.

For more information on the NOLOW feature and 386MAX.PRO, consult your 386MAX documentation or contact Qualitas.

QEMM386

If you back fill with Quarterdeck's QEMM386, the following error message is displayed:
Either memory is insufficient to run KRNL386.EXE or the value of the Windowmemsize entry in the SYSTEM.INI is too large. You need to run the Setup program again.
To work around the problem, use QEMM to disable the base memory back fill by not including the A000 range or by only including A0FF-AFFF.

NOTE: Increasing available memory, adjusting the Windowmemsize value in the [386Enh] section of the SYSTEM.INI file, or running the Windows Setup program will have no effect on the error message.

For more information about including memory ranges, please refer to your QEMM documentation or contact Quarterdeck.

The products included here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.
Modification Type:MinorLast Reviewed:7/7/2005
Keywords:KB87269
©2004 Microsoft Corporation. All rights reserved.