Both speakers on my Dell Vostro 2520 are not working. What can I do?
see if the sound icon is off. Click it and click on troubleshoot.
Do you have multiple sound outputs? Most video cards, laptops included, have an HDMI output which may have been selected while the laptop was plugged into a TV or external monitor.
Is the sound muted? Does the volume icon even show up on the taskbar (it won't if there's no active sound devices).
Do you have a headset set up for Skype or online gaming? Make sure it's not selected as the default Playback Device.
In Win7, you can disable sound outputs and they won't show up in the list of available sources until you enable it. To see if this is the case, click the link to view disabled sources (where your sound inputs are normally listed)
is it because the driver, did you update the driver?
check the driver.