I've searched the web extensively and read pretty much all of the solutions offered up the the screensaver issues in Windows 10 [and the variety of issues indicates Microsoft has some work to do], but none of them seem to work for me.

I don't care about saving my monitor, or watching pretty pictures, or saving power. I need the screensaver for security reasons to lock the screen after an unattended time period. Apparently nobody else uses this feature, or if they do they haven't had a problem, or if they posted on the web I simply haven't found it.

1. This is a clean install of Windows 10 Home. It has an ASUS motherboard, an i5-6600 CPU, 16GB DDR4 RAM. The components are all about 2 months old. Windows 10 x64 Version 1511 10586.63. The original configuration was a single monitor attached to the DVI port of the ASUS motherboard. The screensaver worked fine with that configuration.

2. I installed an Nvidia Quadro NVS 295 graphics card (2 DisplayPorts) with two identical Dell monitors. The latest driver is installed (dated Oct 2015). This is when the screensaver stopped working.

3. I have the screensaver set to "Blank", and the preview function works perfectly well, blanking both monitors.

4. I have no HID devices other than a wireless mouse and keyboard. I have tried a different mouse and keyboard to no effect. I have tried disabling the HID devices one by one to no avail.

5. If I disconnect one monitor at the computer, the screensaver still doesn't come on.

6. I removed the Nvida card and connected the two monitors to the on-board video ports (DVI and HDMI). That made no difference. However, if I disconnected one monitor then the screensaver would work. As soon as I connected the second monitor it stopped working.

7. I found an older Sapphire Radeon video card with DVI and HDMI ports. Surprisingly it had Windows 10 drivers. After hooking everything up again it behaved exactly as the Nvidia card did.

I'm out of ideas. Trying three different video card configurations and the fact that Preview works leads me away from hardware problems.

If anyone has any ideas they would be welcomed!