How to change floating windows back to tabs?

Way back at Adobe MAX in 2014 Michael Ninness put out an amazing video he called Photoshop Power Shortcuts, (or something very similar to that).  It had loads of excellent ideas and tips, but unfortunately, some of it is out of date now, and it looks like Adobe have removed it from YouTube.  Anyway, part of the video was about shortcuts for arranging Photoshop's document windows, and I have been using them ever since.  The two I use the most are Tile Vertically and Consolidate All to Tabs 

None of the answers here fixed my problem. My problem is that I accidentally made a tab to float I didn't know how. It was easy: hold tab + you drag and drop the window. Doing that you can float and pin again the tab to the program.

I tend to switch between them, so I have assigned my own shortcuts to Window > Arrange > Float all in windows, and Window > Arrange > Consolidate all to tabs. I use ctrl+F and shift+ctrl+F, but you can assign whatever you want.

Please check the "Open Document as Tabs" option in the Photoshop preferences

Go to Preferences > Workspace and check Open Documents as Tabs. This option must be enabled to open Photoshop documents in tabs.

If this option is enabled an it doesn't work I would try to reset the preferences to the deafult settings.

To reset the preferences of Photoshop using the steps described here:

Preferences in Photoshop (adobe.com)

Please backup your settings before resetting the preferences. You can check:

Preferences in Photoshop (adobe.com)

Reset the workspace to the default docked configuration and check the relevant preference settings.

Mylenium