NOTE: Before performing any significant repairs, back up your computer's hard drive.
1. Select Start > Power > Restart
If that doesn't work try changing sound enhancements, you may have one set.
- Right-click on the Speakers icon in your taskbar
- Select the Sounds option from its context menu.
- Click on Playback device tab
- Double click Speakers/headphones icon
- on the Speaker Properties menu's click Enhancements tab
- Deselect the boxes next to each enhancement you wish to remove.
If that doesn't work, try updating sound drivers
Update Audio Driver
- Go to Start/window and right-click
- From the list of results click Device manager
- In Device manager under sound, video and game controllers, select your sound card open it
- Select the Driver tab, and select Update Driver.
- Let it download automatically
- Then reboot system