I'm using Windows 10 and today I accidentally hit the key combination: Ctrl+Shift+Win+B.
As a result, the screens went black for about a second and I heard a beep.
This is reproduceable; every time I hit the aforementioned key combination, the same behavior occurs.
Searching on the web I could find nothing about this except a reddit thread in which a user said he observed a similar behavior in Windows 8 by pressing Ctrl+Win+B (no Shift).
So, what is this key combination used for?
Official from Microsoft: "Windows logo key + Ctrl + Shift + B = Wake PC from blank or black screen"
From a discussion with an AMD Radeon driver engineer, it does NOT restart the graphics driver. It does appear to discard the desktop surface buffer and re-create the allocation from DWM (on a healthy system the desktop goes black for a second).
About a year and a half after OP asked their question, "SurfaceDockGuy" posted in reply to a similar Reddit question in /r/sysadmin,
This keycombo actually saves out part of the dispdiag circular log and queues up the data to upload through telemetry indicating the customer had a black screen. That's what the "B" is for. Blackscreen.
The key combo was added to help diagnose instances where the machine is churning along but there is nothing on screen. Pressing it when you don't have a blackscreen just adds noise to the system. A driver reset is a possible side-effect but not the intent of this key.
Source: I worked on the team at MS.
https://www.reddit.com/r/sysadmin/comments/6l7cyk/comment/djua1pi/
Have only found this one, please take a look:
Ctrl+Win+B -> Switch to the program that displayed a message in the notification area.
