Vagrant complains about

Wed, 02 Mar 2016 18:04:21 GMT-ERROR: cdk - Error: Command failed: C:\WINDOWS\system32\cmd.exe /s /c "vagrant plugin install c:\DeveloperPlatform\cdk\plugins\vagrant-registration-1.0.0.gem"
The directory where plugins are installed (the Vagrant home directory)
has a space in it. On Windows, there is a bug in Ruby when compiling
plugins into directories with spaces. Please move your Vagrant home
directory to a path without spaces and try again

When user home directory have spaces in it, because .vagrant.d file path in turn has spaces as well. For instance:

C:\Users\User Name\.vagrant.d