How do I fix No audio output device Windows 7?

7 Best Solutions to Fix No Audio Output Device Is Installed Error

1. Make Sure All External Conditions OK.
2. Run the Playing Audio Troubleshooter.
3. Uninstall Audio Drivers.
4. Install & Update Outdated Drivers.
5. Fix No Sound with Driver Booster.
6. Check for Windows updates.
7. Re-enable the device.