Dell N7110 laptop HDMI port not working after windows 10 update

The HDMI port worked well under Window 7 and was used daily for presentations.

Since the upgrade to Windows 10 no signal from the port is recognised by projectors or TV. This is a major embarrassment as much company kit has no VGA inputs.

What solution is recommended other than scrapping the laptop. Reversion to Windows 7 is not company policy regrettably.