From VNC Server 6.3.2, you can blank the screens of most Windows computers (up to and including Windows 10). This is equivalent to turning the monitor(s) attached to a remote computer off so people in the vicinity can't see what you're doing.

Note: You cannot blank the screens of remote Linux or Mac computers, and there are limitations for some Windows 8 and 10 computers, particularly laptops (see below).

How do I enable screen blanking?

Open VNC Server's Options > Privacy page and turn on Blank screen when users are connected.

Screen blanking is hardware-dependent for Windows 8 and 10, so we recommend you test these systems first to make sure screen blanking will be effective:

Note: Avoid any users connecting remotely while a blanking test is in progress as it can prematurely blank the screens.

What operating systems support screen blanking?

Currently the Windows operating system is supported. Screen blanking for Windows 8 onwards is hardware-dependent, hence the recommendation to test your screen first.

What screen hardware supports screen blanking?

For Windows 7 and earlier, most hardware should be supported.

For Windows 8 and 10, most desktop screens manufactured after 2011 should be supported, including major manufacturers such as Dell and Samsung. The screen must have an independent power button; all-in-one computers are unlikely to work.

Unfortunately, there is not as much support for laptop screens, which are also unlikely to work.

How long does screen blanking last?

For Windows 8 and 10, VNC Server attempts to make screen blanking last for as long as possible. Screen blanking ends if: 

• The blanked screen is powered on again.
• Screens are added or removed from the system.

What if I can’t get screen blanking to work for Windows 8 and 10?

Assuming that your screen was manufactured after 2011 and is not a laptop display, you can try the following:

• Remove any base stations, splitters or repeaters used to connect your screens.
• Update your graphic card driver software to the latest version.
• If there is an option on the screen’s setup menu called MCCS or DDC/CI, enable that option.

If I need to contact you about screen blanking, what information do you need?

We need the following information:

• A debug server log, after you have performed the screen blanking test.
• The manufacturer and model of the screens that failed to respond to screen blanking.
• How the screens are connected to your system (HDMI, VGA, DVI, and so on).
• The manufacturer and model of your graphics card.