Microsoft provided access to a beta release of Windows Azure Drive (announced as XDrive at PDC 2009). With Windows Azure Drive, your Azure apps running in cloud can use existing NTFS APIs to access a durable drive. This can significantly ease the migration of existing Windows apps to cloud, enabling customers a more seamless migration experience while simultaneously reducing the amount of time it takes to move their applications from your own Windows environment to a Azure environment. Windows Azure app can read from or write to a drive letter (e.g., X:\) that represents a durable NTFS volume for storing and accessing data. The durable drive is implemented as a Windows Azure Page Blob containing an NTFS-formatted Virtual Hard Drive (VHD). For the beta release of Windows Azure drive, customers will be billed only for the storage space used by the Page Blob and the read/write transactions to the Page Blob. This’ll be incorporated into standard Windows Azure usage rates and there’ll not be a separate line item on the bill. Customers using February 2010 Windows Azure SDK should make sure they’re running Guest OS 1.1 to start using Windows Azure Drive. New customers should visit WindowsAzure.com to sign up for Feb 2010 Windows Azure SDK in Guest OS 1.1 to also start using Windows Azure Drive.