Here are some troubleshooting steps that may help.
- While your playing sound, right click on the speaker icon and select "Open Volume Mixer".
- If you're using media player or whatever software you're using to play sound it should show in Volume Mixer and adjust the volume from there.
- If this will not work, uninstall/reinstall the sound driver.
- Go to Device Manager and uninstall the Sound Driver.
- Once done, reboot your laptop and it should reinstall automatically.
- If it doesn't reinstall, download and install the sound driver from the manufacturers site.
- After installing the latest driver do test it again.