In December 2008 the BBC moved to an Adobe AIR-based client that downloaded content via HTTP rather than P2P. The new system replaced the Windows DRM system with Adobe's own. DRM software prevents it being directly copied to another medium (e.g. another computer or CD-ROM), and allowed the BBC to control how long the programmes remain watchable. Programmes were available for download for seven days following broadcast. Once a programme is downloaded a user had thirty days to start watching it; after starting to watch, a programme remained available for the next seven days. Using the online streaming service most programmes became unavailable from the website after 7 days.