"Himem.sys is missing" error when rebooting after installing Norton AntiVirus Ve



Document ID: 98050320

 

Posted Date: 1999-07-19

 

Last Updated: 1999-07-15

 

Distribution: View Public Website

 

Issue
When warm booting (restarting) under Windows 95 or Windows 98 the system will display the following error message: "unable to control A20 line" and "Missing Himem.sys". This can occur after installing Norton AntiVirus version 5.x.
Procedure
To prevent the problem from occurring, follow these steps to make changes to the computer's startup files:
  1. Restart the computer.
  2. When "Starting Windows 95..." appears on the screen, immediately press F8.
    This displays the Windows 95 Startup Menu. Note:In Windows 98, hold down the Ctrl key during startup to access the Startup Menu.
  3. Select Safe Mode - Command Prompt Only and press Enter.
  4. At the C:\> prompt, type: EDIT AUTOEXEC.BAT and press ENTER
  5. You should now have a blue screen in which you can edit text. At the very beginning of the file, add the following line: SET DOS16M=2
  6. Press Alt+F to open the File menu. Choose Exit and press Enter. When prompted to save changes, answer Yes and press Enter.
  7. You will now be back at the C:\> prompt. Type: EDIT CONFIG.SYS and press ENTER
  8. In the text editor, find a line which refers to the HIMEM.SYS file.
  9. At the very end of that line, type a space, then type the following: /M:1
  10. If the CONFIG.SYS file does not contain a line with HIMEM.SYS, add the following line: DEVICE=C:\Windows\HIMEM.SYS /M:1 You may need to alter the path to point to your Windows folder if it is different than the line above.
  11. Press Alt+F to open the File menu. Choose Exit and press Enter. When prompted to save changes, answer Yes and press Enter.
  12. Restart the computer. It should now boot normally.
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