The way Windows Phone 7 handles updates is different from previous versions, and solves some of the common problems from the past. As mobile devices have evolved, some vendors have learned painful lessons about the challenges involved in making ROM updates. Even when such updates worked, issues like app re-installation and reconfiguration sometimes made for a less-than-pleasant user experience.
For Windows Phone 7, Microsoft has put to good use some existing technology they’ve been fine-tuning for years. There’s no longer any need to wonder where updates can be obtained—with Windows Phone 7, the process is handled through Microsoft Update. Users see a notification on their phone when updates are available, and the actual updates are applied when they next connect their phone to their PC and use the Microsoft® Zune®–based update process.
If there is an issue with an update, it’s also possible to revert to a pre-update configuration because the update process automatically saves a snapshot of the device state before it starts the update process.
All apps are acquired through the Marketplace Hub, so Microsoft provides update notifications for all apps—regardless of who developed them. The update process doesn’t mess with data, settings, or other apps, either. App updates can be done over-the-air (OTA), but ROM updates need a PC connection.
For more info, see the article Windows Phone 7 device update on the Windows Phone 7 Guides for IT Professionals page on the Microsoft Download Center.