There are many tutorials on how to install Linux subsystem under Windows, you can baidu by yourself. I used the way of Downloading and installing Microsoft Store, but I reported the following error when launching Ubuntu:
Error: 0x800703fa – Press any key to continue
Solution: turn on service Management and restart LxssManager service solution.

Each subsystem usually has a subsystem service process and a kernel driver, in the case of Windows subsystems, the well-known CSRSS.exe and Win32k.sys, respectively. For WSL, the subsystem service process LxssManager that runs as a system service. The LXSSManager service supports running native ELF binaries. This service provides the infrastructure needed to run ELF binaries on Windows.

PS: Linux system mount location
C: \ Users \ {UserName} \ AppData \ Local \ Packages \ CanonicalGroupLimited UbuntuonWindows_79rhkp1fndgsc \ LocalState \ rootfs