Seattle-based Amazon Web Services announced today that it has added Microsoft Windows Server applications into its AWS Free Usage Tier, the introductory level of AWS which helps developers get started using its cloud computing services. Amazon said it will allow customers to take advantage of 750 hours of Amazon Elastic Compute Cloud (EC2) usage per month at no charge, for one year, running on Windows Server. Amazon previously only provided the free usage on its Linux instances. Both programs are designed to help companies get their software up and running on AWS without incurring usage fees during that development and testing time. Amazon said that customers using its Windows Server capabilities are the U.S. Treasury's Treasury.gov website, and Knovolo, a mobile marketing firm.