This WP-CLI plugin makes the process of moving sites from single WordPress sites to a Multisite instance (or vice-versa) much easier. It exports everything into a zip package which can be used to automatically import it within the desired Multisite installation.
When I import a subsite into a Windows system, at the stage of extracting tables, I get an error:
Extracting zip package... Importing tables... Error: sed not present, please install sed
I'm just usin this command, nothing special: wp mu-migration import all subsite-test.zip --blog_id=1
Also, I found and installed this sed application https://sourceforge.net/projects/gnuwin32/files/sed/4.2.1/sed-4.2.1-setup.exe but it's not helped for me