Reference number: CH000318

Himem.sys and/or emm386 errors.

Issue:

Himem.sys and/or emm386 errors.

Cause:

This issue can be caused by any of the below causes.

1. Missing either himem.sys and/or emm386.exe
2. Autoexec.bat and/or Config.sys have conflicting data or programs causing this issue
3. Himem.sys or emm386.exe are corrupt
4. Memory in computer is bad or corrupt

• If you are encountering 'himem.sys missing or corrupt' see document CH000425.
• If you are experiencing an emm386 error code please refer to our EMM386 page.

Solution:

Missing either himem.sys and/or emm386.exe

Verify that both himem.sys and/or emm386 are present on the computer by typing the below 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 that you have typed in the command properly it is likely the file is missing. Either of these files can generally be copied from another computer or bootable floppy diskette.

Autoexec.bat and/or Config.sys have conflicting data or programs causing this issue

It is possible that memory managers or other TSRs have conflicting information to cause himem or emm386 errors. If you have Windows 9x or above, attempt to rename those files by typing the below commands.

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

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

If you are running Windows 3.x or MS-DOS 6.x or below, 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 the F5 key 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 the file with the line that caused your error and temporarily remark that line. Additional information about the autoexec.bat and the config.sys and how to remark the lines can be found on our autoexec.bat and config.sys page.

Himem.sys or emm386.exe are corrupt

It is possible that the files themselves are corrupt causing the memory managers to load improperly or not at all. Attempt to 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 computer is bad or corrupt

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

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

If, however, you are able to successfully boot from a bootable diskette it is likely there may be another software or hardware related issue. We recommend that you attempt to format all information on the hard disk drive and restore the Operating system. Additional information on how to do this can be found on document CH000186.