How to install Drush 8 on Windows 10? I am currently running Drush 7 and its working fine for D7. 

But I want to run it for D8 site. I have also seen many post where it is mentioned that Drush 7 support D8 but its not true.

So i am trying to install Drush 8.

Try to run below command

composer global require drush/drush:8.*


Or

composer require drush/drush:dev-master


./composer.json has been created
Loading composer repositories with package information
Updating dependencies (including require-dev)
Your requirements could not be resolved to an installable set of packages.


  Problem 1
      - Installation request for drush/drush dev-master -> satisfiable by drush/drush[dev-master].
      - drush/drush dev-master requires consolidation/robo dev-master -> satisfiable by consolidation/robo[dev-master] but these conflict with
  your requirements o r minimum-stability. Installation failed, deleting
  ./composer.json.


But unable to get success. Any suggestion how achieve this?
Finally...

using this command

 composer global require drush/drush:8.*


But i need to refer few steps before running this command.

  composer.json  # Removed the line containing drush like below



  {
          "require": {
              "drush/drush": "7.*"
          }
      }


composer global update
composer global require drush/drush:8.*


source https://github.com/drush-ops/drush/issues/2006