Windows server minimum requirements 

To provision a Windows 2008 or 2012 (x86 or 64-bit) server, you will need to hold a minimum of a "5-Block" account because Windows images require 20GB of disk space and a minimum 1.5-2GB of RAM to run correctly. Windows templates which include Exchange or SQL will have even greater requirements. If you have any questions, please feel free to submit a support request or email support@netsonic.net .

Windows server 2008 and 2012 images are 10-15GB in size depending upon the template chosen.