Just purchased a surface pro and i accidentally disabled the speakers and can't reverse it. Help!

Set speakers to default device.

a.Go to Search from the Start page and select Settings from the drop down.

b.  Type in adjust sound, and select Manage Audio Devices from the list. 

c.  Select the Playback tab. You should see an icon for speakers which should be marked Default Device

Reboot the surface.

• Press Windows Key + C or Swipe in from the right edge of the screen,
• Tap or click Settings.
• Tap or click the speaker icon and adjust the slider down or up

Sound should now be working.

More often than not when a device isn't working it is because the driver has become corrupted. Re-installing a fresh copy should help

Read all about updating drivers by my partner JMH3143 here http://answers.microsoft.com/en-us/windows/wiki/windows_other-hardware/updating-a-driver/a5e6345e-af9b-4099-bef0-8d22254aa1c1?tm=1436753520149 http://windows.microsoft.com/en-us/windows7/Update-a-driver-for-hardware-that-isnt-working-properly?SignedIn=1

http://captaindbg.com/how-to-update-drivers-on-windows-7/   (works on win 8 & win 10)