Himem.sys and emm386 errors

Updated: 12/31/2020 by Computer Hope
himem emm386 errors

Below is a listing of enn386.exe and himem.sys errors you may encounter while booting a computer with MS-DOS or Windows.

Missing either himem.sys or emm386.exe

Verify that both himem.sys and emm386 are present on the computer by typing the following commands at the MS-DOS prompt.

cd\ <press Enter>
cd windows <press Enter>
dir himem.sys <press Enter>
dir emm386.exe <press Enter>

If, when typing dir for either the himem.sys or the emm386.exe file, you receive a message file not found, first verify that the file was typed in properly. If it appears you typed in the command properly then the file is missing. Either of these files can be copied from another computer or bootable floppy diskette.

Autoexec.bat or config.sys have conflicting data or programs causing this issue

Memory managers or other TSRs can have conflicting information and cause himem or emm386 errors. If you have Windows 9x or above, rename those files by typing the following commands.

cd\ <press Enter>
ren autoexec.bat autoexec.ch <press Enter>
ren config.sys config.ch <press Enter>

Once the files are renamed, reboot the computer to see if the issue persists. If the issue persists, skip to the next section.

If you're running Windows 3.x or MS-DOS 6.x or earlier, boot the computer step-by-step to verify if a line in the autoexec.bat or config.sys is causing your issue. To do this, as the computer is booting, press F5 when you see the message Starting MS-DOS. You should be prompted to say Yes or No to load each line. Load each line until you get the error.

Once the error is determined, edit the file with the line that caused your error and temporarily remark that line. For additional information about remarking the lines of your autoexec.bat and config.sys files, see autoexec.bat and config.sys page.

Himem.sys or emm386.exe are corrupt

The files may be corrupt and causing the memory managers to load improperly or not at all. Replace these files with a known good himem.sys and emm386 by copying the files from a bootable floppy diskette or copying from another computer. Ensure that before these files are copied over to the computer experiencing the issue that the himem.sys and the emm386 files are deleted first.

Memory in the computer is bad or corrupt

If you have completed all of the above recommendations and continue to experience the same issues, you may be experiencing a memory issue. To determine this, boot from a known good bootable diskette that loads the himem.sys and the emm386.exe files.

If, when booting from the floppy diskette you experience the same errors, there is a hardware issue with your computer memory or your motherboard. In this case, we recommend the memory be replaced or that the computer be taken to a local repair store for examination.

However, if you can successfully boot from a bootable diskette, it's likely there may be another software or hardware related issue. We recommend you erase all information on the hard drive and restore the operating system.