To easily install the Crystal Preview on Windows you can use Scoop. Be aware of the fact that Crystal on Windows is not yet complete.
Before you start the installation, you must ensure that the required packages are installed.
Install
scoop bucket add crystal-preview https://github.com/neatorobito/scoop-crystal
scoop install crystal
Upgrade
When a new Crystal version is released you can upgrade your system using:
scoop update
scoop update crystal