Please try to uninstall and reinstall the sound driver of your laptop.
- Press Windows + R then type in "devmgmt.msc" in the Run box that will appear.
- Expand Sound from the list then right click on the device underneath sound and click on uninstall.
- Reboot the PC so the laptop would reinstall the sound driver on it's own.
- If after reboot and there's still no sound, download and install the latest driver from the manufacturers website
- Lastly, System Restore would be the last step. Restore the PC into a earlier date and time when you're still getting sound.