an image-based system that ensures point-in-time-based restoration of either entire PCs or specific files and folders. Complete bare-metal restores are initiated through a restore bootable CD, file based restores are initiated through the WHS client software which allows the users to open a backup and "drag and drop" files from it. This technology uses Volume Shadow Services (VSS) technology on the client computer to take an image based backup of a running computer. Because the backup operates on data at the cluster level, single instancing can be performed to minimize the amount of data that travels over the network and that will ultimately be stored on the home server. This single instancing gives the server the ability to store only one instance of data, no matter if the data originated from another computer, another file, or even data within the same file. Computer backup images are not duplicated on the server, so if a server hard drive fails, backups could be lost. The "Server Backup" feature added in Power Pack 1 does not include duplication of backup images. Remote File Access The system also offers an SSL secured web browser based interface over the Internet to the shared file stores. The release version offers access to the web interface via a free Windows Live-provided URL, which uses Dynamic DNS. The web interface also allows the uploading to and downloading of files from the content stores. However, there is a limit of 2 GB for a single batch of upload. Remote Desktop Services The system also supports Terminal Services Gateway, allowing remote control of the desktop of any Windows computer on the home network. Currently supported systems are those which would normally support Remote Desktop: Windows XP Professional, Tablet and Media Center editions, Windows Vista Business, Enterprise and Ultimate editions and Windows 7 Professional, Enterprise and Ultimate editions. The web interface also supports embedding the Remote Desktop ActiveX control, to provide remote access to home computers from within the web interface directly. Remote sessions can also connect to the Home Server console to configure the server over the internet. Add-Ins Windows Home Server allows for developers to publish community and commercial add-ins designed to enhance the Windows Home Server with added functionality. As of January 2010, nearly 100 of these add-ins have been developed for WHS, including applications for antivirus & security, backups, disk management, automation, media, network/power management, remote access,