The single root système de fichiers was located here until Windows 10 Fall Creators update (released in Oct. 2017):
%LOCALAPPDATA%\Lxss\rootfs
Par exemple, C:\Users\Vigo\AppData\Local\Lxss\rootfs\
Other mount points are located one level up in the lxss directory. Par exemple, your own home directory within Linux will be in %LOCALAPPDATA%\Lxss\home.
Starting from the Fall Creators update, it is possible to install more than one instance of Linux and run them in parallel. The existing instance (a.k.a. legacy) will stay in its directory but new instances created are located under:
%LOCALAPPDATA%\Packages<distribution_specific_name>_<random_string>\LocalState\rootfs
Par exemple, my Ubuntu 18.04 installation is located under the CanonicalGroupLimited.Ubuntu18.04onWindows_79rhkp1fndgsc directory.
Warning: Beware not to create, modify or delete files located under the lxss or distribution specific tree from Windows.
Exploring and reading files is the only harmless operation. See this Microsoft blog page for details.
Notez que starting from Build 1903, there is an alternative way to access the files of a running distribution that doesn't exhibit the previously mentioned issues.
Just use the path \\wsl$\<distribution_specific_name>\ and you'll be able to create and modify files. The AppData is still not a supported way to access files with build 1903.