Note: Some updates shown in the update list aren’t downloaded with the other updates, and you aren’t notified to install them (described in KB910340). Some customers call support believing that WU isn’t working correctly, because it isn’t downloading or notifying them about some updates. These updates are held back by WU. You can download and install them manually through WU, but WU won’t automatically download or notify you about these specific updates until the WU servers make them “available” for your computer. We gradually allow computers to start downloading larger updates, like Service Packs, because they are bigger downloads that require more network bandwidth to download. If an update is held back from your computer, it will not prevent WU from notifying you on the system tray after all of the “available” updates have been downloaded.