NOTE: You, the customer, are solely responsible for data security. WinBook strongly recommends that you perform a backup of all personal data contained on your system prior to performing this procedure. Warning: WinBook will NOT be held responsible for any data loss incurred during this process.

Portions of Norton AntiVirus or Norton SystemWorks that is installed on the computer has caused this error.  When installed, both of these two applications can cause some booting problems if the computer is restarted immediately after installing either applications.  If the computer is shutdown immediately, then an error on boot may not be displayed.  These error messages include HIMEM.SYS is missing..., and Unable to control A20 line.

There are two ways to rectify the above described problems.

First Solution:
1. Restart the computer in Safe mode command prompt only.
2. Type EDIT AUTOEXEC.BAT to open the AUTOEXEC.BAT file in the DOS Edit program.
3. Locate the following line:

C:\PROGRA~1\NORTON~1\NAVDX.EXE /STARTUP

4.  Add REM to the above line so that it reads as the following:

REM C:\PROGRA~1\NORTON~1\NAVDX.EXE /STARTUP

5. Type the following keys individually to save and exit from the file: Alt, F, X, Y.
6. Hold down the power button for 10-15 seconds until the computer is shut off. Restart the computer and the error message should not be displayed. If you still get an error message, please refer to the second solution.

Second Solution:
1. Restart the computer in Safe mode command prompt only.
2. Type EDIT CONFIG.SYS to open the CONFIG.SYS file in the DOS Edit program.
3. The CONFIG.SYS file should include the line as it appears below. You may need to append a Space and /M:1 only or add the entire line.

DEVICE=C:\WINDOWS\HIMEM.SYS /M:1

4. Type the following keys individually to save and exit from the file: Alt, F, X, Y.
5. Hold down the power button for 10-15 seconds until the computer is shut off. Restart the computer and the error message should not be displayed. If you still get an error message, please contact our phone support number listed above.

Below are the links to Symantec's knowledge base about the above two problems and the applications associated with them:

Norton AntiVirus link: HIMEM.SYS is missing on boot

Norton SystemWorks: HIMEM.SYS is missing on boot

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Disclaimer: This information is being provided to you as a service from the Technical Support Department of WinBook Computers. It is intended to assist you in the resolution of your technical problems or questions. If you feel uncomfortable implementing any of the information or suggestions contained herein then you should e-mail the WinBook Technical Support Department. WinBook will not be held responsible for any loss of information, data or programming as a result of the use of this TechNote.