All answers I could quickly find on this topic involve either the tip Molly gave or using an application (or coding it yourself). For example (I haven't tried this), Close All Windows.
Also, by pressing Ctrl + Shift + Esc you get the Windows Task Manager, where you can see all running applications at once (among other things), select them, and End Task them.
Answer from Adriano Varoli Piazza on Stack ExchangeAll answers I could quickly find on this topic involve either the tip Molly gave or using an application (or coding it yourself). For example (I haven't tried this), Close All Windows.
Also, by pressing Ctrl + Shift + Esc you get the Windows Task Manager, where you can see all running applications at once (among other things), select them, and End Task them.
I like to see my open windows ungrouped, but realized that this i.e. closing multiple windows at once was a problem with such a setting. A less time-taking method would be to use the command line like this :
taskkill /im explorer.exe -f
And then restart explorer using :
explorer
Caution : This will cause processes like file copying on the default Windows interface to abort.
Quickly close all windows at once
Is there a button that closes out all windows at the same time? Tired of closing them all one at a time.
Ever wanted a keyboard shortcut that instantly kills all your firefox windows and tabs without any warning? Ctrl+Shift+W
visual studio code - Keyboard shortcut for Close all tabs except current working tab - Stack Overflow
Videos
There is no keyboard shortcut I know of and after checking Google forums, neither does anyone else.
You could use the extension Close Inactive Tabs instead - This adds a button which closes all other tabs except the active one.
I wrote this extension so that we can assign shortcuts for closing tabs to the right / left / other tabs / pin / unpin tab. Let me know if you can use it.
Update: It's temporarily off from Chrome Store and I'm working to get it back.Meanwhile, you can install it from here: https://github.com/diophung/close-chrome-tabs

Update 2019/06/10:
Still works with Chrome 75

Not to be confused with Ctrl+W, your go-to keypress to close one tab.
Ctrl and Shift are so far apart, right?
You don't even get a warning.