How to fix the Call of Duty 4: Modern Warfare Multiplayer crash on startup

call-of-duty-4-modern-warfaretechnical-issues

I have installed Call of Duty 4: Modern Warfare on my Windows machine. The single player mode works perfectly, but when I try to run COD4 Multiplayer it crashes on startup. Windows then shows the following error message:

iw3mp.exe has stopped working.

What can I do to fix this?


Disclaimer: I’ve made this thread to collect the various solutions to this problem that are scattered across the interwebs. Please add an answer if you have an alternative solution! All the solutions posted below have apparently fixed the problem for many people, but not for me — so I’m still looking for a solution to play CoD4 on my new gaming PC.

Best Answer

This is a very common problem due to sloppy programming on Activision’s part. It is related to the system’s audio device, e.g. a problem with your sound card drivers, mostly if it is a Realtek or a Sigmatel onboard sound card.

Here are some things you can try:

Enable Stereo Mix

  1. Right-click the volume/speaker icon in your system tray, and select Recording devices. (If you don’t have the icon in your system tray, open Control PanelHardware and SoundSoundRecording.)
  2. Right-click and select View Disabled Devices. The device Stereo Mix appears.
  3. Enable the Stereo Mix device.
  4. Start the game.

If that doesn’t solve the issue, try the next suggestion.

Use a mic & headphones

  1. Plug in a microphone into the microphone jack.
  2. Plug in headphones into the headphone jack.
  3. Right-click the volume/speaker icon in your system tray, and select Recording devices. (If you don’t have the icon in your system tray, open Control PanelHardware and SoundSoundRecording.)
  4. Set Microphone as the default input device.
  5. Switch to the Playback tab.
  6. Set Headphones as the default audio playback device.
  7. Start the game.

If that doesn’t solve the issue, try the next suggestion.

Realtek: Disable front panel jack detection

If you have an Realtek onboard sound card, this might help:

  1. Double-click the orange volume/speaker icon in your task bar. This opens the HD Audio Manager.
  2. Click on the folder icon in the upper right edge.
  3. Check Disable front panel jack detection. This forces the driver to load microphone support even without a mic plugged in. Close the top-most window.
  4. In case you’re using the digital output, make sure that the Digital Output device is set as the default. To do that, click on Digital Output in the upper bar and on Set Default Device next to the volume adjuster.
  5. Start the game.

If that doesn’t solve the issue, try the next suggestion.

Sigmatel: install updates

If you have a Sigmatel onboard sound card, install all Windows updates and the latest Sigmatel drivers from http://www.dell.com/.

Remove the mssmp3.asi file

  1. Go to the installation folder of CoD4.
  2. Enter the miles folder.
  3. Rename the file mssmp3.asi to mssmp3.asi.bak.
  4. Start the game.

If that doesn’t solve the issue, try the next suggestion.

Update PunkBuster

Make sure PunkBuster is updated to the latest version.

Install Call of Duty 4 patches

Install all patches up to at least v1.5. (Currently, the latest available patch is v1.7.)

If that doesn’t solve the issue, try the next suggestion.

Reinstall sound card drivers

Before continuing, please make note of the make and model of your sound card prior to removing it in order to aid in reinstallation at a later date.

Uninstall your sound card drivers as follows:

  1. Open StartRun and enter sysdm.cpl to display the System Properties dialog box.
  2. Go to HardwareDevice Manager.
  3. Expand Sound, video, and game controllers.
  4. Right-click the sound card driver and then select Uninstall.

Then let Windows install its default sound drivers.

If that doesn’t solve the issue, try the next suggestion.

Update BIOS

If you are running the game from a secondary partition, download and install the latest BIOS updates from your motherboard manufacturer.

If that doesn’t solve the issue, try the next suggestion.

Disable onboard sound in BIOS

Disable the onboard sound card in the BIOS.