Warning:
  Do not install Flutter in a directory like 
  C:\Program Files\ that requires elevated privileges.

If you don’t want to install a fixed version of the installation 
bundle, you can skip steps 1 and 2. Instead, get the source code 
from the Flutter repo on 
GitHub, and change branches or tags as needed. For example:

C:\src>git

clone

https://github.com/flutter/flutter.git

b

stable

You are now ready to run Flutter commands in the Flutter Console.

Update your path

If you wish to run Flutter commands in the regular Windows console,
take these steps to add Flutter to the PATH environment variable:

From the Start search bar, enter ‘env’
and select Edit environment variables for your account.