Hi Joane,
An outdated or corrupt display adapter may cause your external monitors not to be recognized by your Surface device. Updating, rolling back or reinstalling the driver can help resolve the issue.
In many cases, downloading and installing the latest updates for Windows and your Surface resolves this kind of issue. On how to install Surface and Windows updates, click here.
If installing the Surface and Windows updates didn't work, try rolling back the driver.
- Open Device Manager.
- Under Display adapter, right click the display driver.
- Choose Properties.
- Click the Drivers tab.
- Click Roll Back Driver.
Try to uninstall the display driver if roll back didn't work.
- Open Device Manager.
- Under Display adapter, right click the display driver.
- Choose Uninstall.
- Restart your device and let Windows reinstall the driver.
Let us know if you need further assistance.