1. Try uninstalling the sound driver from the Device Manager: My Computer-right click\Manage\Device Manager\Sound card right click \ Uninstall \ Restart the computer and check if you now have audio. This can make the Plug and Play service to reinstall the driver.
If it did not install, try installing in different modes: Automatic installation searching in windows Update, Automatic installation searching in your computer, or manual installation from the drivers already in your computer.
My Computer-right click\Manage\Device Manager\Sound card right click \ Update driver \
2. Select "yes this time only" to search for the driver in windows Update, or
3. No, not this time to search in your computer \ Next \ Install the Software automatically (recommended)....
4. If it doesn't install automatically, try manually with "Install from a list or specific location (Advanced)\Next\Don't search. I will choose the driver to install\Next\and Next should reinstall the previous driver.
5. If nothing happens, download a driver update from your laptop's manufacturer website:
To download the driver from the laptop's manufacturer website... look for the model page support, downloads, or drivers. If you find it and download it, execute the driver file and press the "next" button when it highites on each installation step. After finish, restart the computer, wait a few minutes, and check if you have sound.
6. If still nothing, install the driver you downloaded following each step above; starting with Automatic installation, and follow with Manual installation if necessary.