Fix Mmsystem.dll Errors on Windows 98 and Windows ME

You may receive one of the following General Protection (GP) error messages on your Windows 95, Windows 98, or Windows ME computer:

Rundll32 - This program has performed an illegal operation and will be shut down.

Rundll - This program has performed an illegal operation and will be shut down.

When you click the Details button, you may be able to view information similar to the messages given below:

RUNDLL32 caused a General Protection Fault in module MMSYSTEM.DLL

RUNDLL caused a General Protection Fault in module MMSYSTEM.DLL at 000a:00000032

This Mmsystem.dll error is usually generated after the Add New Hardware control panel tool is used on a Windows computer.

Cause of the Error

This error occurs when:

  • The following line is missing from the [boot] section of the System.ini file on your Windows PC:


  • System.ini is replaced with the System.cb file.

Resolution Method

To resolve this error, perform the following steps:

  1. Search for the System.ini file on your PC and open it in a text editor tool, such as Notepad.
  2. Go to the [boot] section of the file and add the following line:
  3. drivers=mmsystem.dll

  4. Save the System.ini file and then close it.
  5. Reboot your PC.

If the system.ini is replaced with the system.cb file, then perform the following steps to create a new system.ini file:

  1. Open the Command Prompt window.
  2. Next, run the following commands, and then press Enter:
  3. ren system.ini system.bak

    Note: If no system.ini exists on your PC, this command will fail.

    copy system.cb system.ini
    edit system.ini

  4. A text editor will open. Press Enter at the beginning of the file to move the cursor to a blank line.
  5. Add the following lines to the system.ini file:
  6. [boot]

  7. Next, move on to the section that starts with [386Enh], and add the following line right below the heading:
  8. mouse=*vmouse

  9. Save and exit the System.ini file.
  10. Exit Command Prompt and then restart your PC.

Your PC may freeze up and the following error message may appear on a blue screen when you start your PC after installing Windows Millennium Edition (Me):

msgsrv32 has caused an error in mmsystem.dll

Additionally, when you start the PC in Safe mode, the PC may display a blank desktop with no taskbar and desktop icons.

Cause of the Error

This error usually occurs due to a damaged Setupx.dll file.

Resolution Method

  1. Open your PC in MS-DOS mode with CD-ROM support.
  2. Use the “dir” and “cd” commands to locate the Setup.dll file.
  3. When you find it, use the “cd” command to change to the directory in which the Setup.dll file is located.
  4. Use the “ren” command to rename the file to setupx.bak.
  5. Insert your Windows ME CD in the CD-drive,
  6. Type “Ext” and then follow the screen instructions to extract a new copy of the Setupx.dll file to your PC.
    Note: If you are able to boot into Windows ME Normal mode with the help of a startup disk, you may perform the above steps by searching for the setupx.dll file using the Search feature. Next, you may rename the file and extract the Setupx.dll file from the Windows ME CD.

One of the major causes of corrupt files on Windows computers are virus and spyware infections. This is the reason why it is recommended that you use reliable antivirus and antispyware tools, such as STOPzilla Antivirus and Spyware Cease to regularly scan your PC to keep it free from unwanted malicious files and programs.