Error Message: Explorer Has Executed an Invalid Instruction in Msls31.dll (299992)


The information in this article applies to:

  • Microsoft Windows 98 Second Edition
  • Microsoft Windows 98
This article was previously published under Q299992

SYMPTOMS

When you start Windows, you receive an error message similar to the following:
Explorer has executed an invalid instruction in MSLS31.DLL
When you click Close, the error message reappears.

Note: You may also receive this message when opening Microsoft Internet Explorer, when you attempt to browse the Internet, or when you open the My Computer folder.

CAUSE

This issue may occur when the Msls31.dll file is damaged.

RESOLUTION

To resolve this issue, extract a new copy of Msls31.dll from the Windows 98 compact disc (CD) to the Windows\System folder. To do this, follow these steps:

Note: If you have updated Internet Explorer to a later version than the one that is included with Windows 98, replace the Msls31.dll file by using steps from the following Microsoft Knowledge Base article:

194177 Description of the Internet Explorer Repair Tool

  1. Quit all running programs.
  2. Click Start, point to Programs, point to Accessories, point to System Tools, and then click System Information.
  3. In Microsoft System Information, on the Tools menu, click System File Checker.
  4. In the System File Checker dialog box, click Extract one file from installation disk.
  5. In the Specify the system file you would like to restore box, type msls31.dll, and then click Start.
  6. In the Extract File dialog box, in the Restore from box, type drive:\Win98 where drive is the drive letter of the CD or DVD-ROM drive that contains your Windows 98 CD, and the click OK.

    Note: If your computer has an Original Equipment Manufacturer (OEM) installation of Windows 98, the Windows installation files may also be found in the following folder:

    C:\WINDOWS\OPTIONS\CABS

  7. In the Backup File dialog box, click OK. If a "The backup folder does not exist. Do you want to create it" message appears, click Yes.
  8. Click Yes to the "The file has been successfully extracted" message that appears, and then click Close.
  9. Restart the computer.

MORE INFORMATION

For additional information about extracting Windows files, click the article number below to view the article in the Microsoft Knowledge Base:

129605 How to Extract Original Compressed Windows Files

Modification Type:MinorLast Reviewed:12/20/2004
Keywords:kberrmsg kbprb KB299992
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