Install Setps

Open PowerShell as Administrator
Run : Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux
Restart your computer when prompted.
Install the Linux Distribution on your Windows 10, Please install Ubuntu 18.04 LTS for WSL from the flowing link: Ubuntu 18.04 LTS
Note: Windows* 10 build version 16215.0 or higher is the recommended operating system version.
From the distro's page, select "Get"
Now that your Linux distro is installed, you must initialize your new distro instance once, before it can be used. You will be prompted to create a new user account (and its password).
Most distros ship with an empty/minimal package catalog. We strongly recommend regularly updating your package catalog, and upgrading your installed packages using your distro's preferred package manager. On Debian/Ubuntu, you use apt:
sudo apt update && sudo apt upgrade
Install additional distro packages required for Nios® II EDS using the following command:
sudo apt install wsl
sudo apt install dos2unix
sudo apt install make
Once the installation is complete, the WSL is installed.

Reference

Section 2.1 "Installing Windows Subsystem for Linux (WSL) on Windows" of Nios II Software Developer Handbook