Hi,
Welcome to the Community.
* Check the volume Mute/Unmute.
* Check for the Windows Start-Up Sound.(When you start your computer you will get windows sound)
* Check the Audio Drivers in Device Manager.Please uninstall/reinsatll the drivers from support.dell.com
and if you have windows 7 than uninstall the drivers and than restart the computer, drivers will get installed automatically.
* Update the Audio Driver and the BIOS from support.dell.com.
* Ask if the issue occurs in a specific application.
* Check with external speakers/headphones.
Thanks,
Amardeep
Dell | Social Media Outreach | Global Social Media & Community