Microsoft released a new hotfix for Windows 7 Media Center which resolves a problem some users have experienced whereby the Music Library appears to be in a perpetual state of re-building, with the UI unresponsive. In KB 981770, Microsoft states: “You frequently experience a music library issue when you access the music library in Windows Media Center or in Windows Media Center Extender. You access a music library in Windows Media Center or in Windows Media Center Extender on a computer that is running Windows 7. However, it takes a long time before the music library becomes available. This issue frequently occurs when you perform one of following actions: You shut down WMCE by pressing power button. Note In a typical situation, you click Tasks and then click Close to shut down WMCE. You shut down computer unexpectedly. For e.g., you shut down computer by pressing power button while you’re using WMC,” explain Microsoft.