Sound/Mixer icon has red cross. No Audio Output Device is installed.

[eiger3970]

Windows 7 32-bit won't play sound.

Device Manager\Sound, video and game controllers\High Definition Audio Device ok.
Double click and window says:
High Definition Audio Device Properties\General: Device status says This device is working properly.

Speakers are plugged in and make a crackle when plugging in to correct holes.

Mystery?

 

[fireberd]

If it's shown as "working properly" in the Device Manager, the speaker icon you have can also be because the sound is muted.

You show "High Definition Audio Device" rather than the actual sound device which suggests you have the generic Windows/Microsoft installed sound driver rather than the actual sound driver from the motherboard vendor. In many cases the generic Windows driver does not work or work correctly.

You can try and uninstall/reinstall by RIGHT clicking on the entry for the sound and then LEFT click "Uninstall" (DO NOT check the box to uninstall the drivers) then restart the PC and when Windows starts it will detect and reinstall the sound. This fixes a lot of flakey problems.

If the uninstall/reinstall does not fix it, the next step is to get the correct sound drivers and install them.