Motorola Milestone (Known as Motorola DROID in USA) is one of the early super power Android smartphones of the World released back in November 2009 with Android 2.1 
Éclair installed. After such a long time it will be upgraded by Android 2.2 froyo. But the firmware upgrade is not available Over-The-Air. You must have your moto droid connected to your computer via a cable to carry out this Android 2.2 firmware upgrade.
This Android Froyo firmware upgrade has numerous new features, tons of shortcuts, and enhancements such as 3G Mobile Hotspot performance and connectivity for your Motorola Milestone. It also brings flash-support for the web browser and improved JavaScript performance. To view the complete change log you can see this pdf file published by Motorola.
Keep these words in mind before going to upgrade your Motorola Android-
1. Exhaustive testing process has concluded that users may experience some adverse effects associated with the upgrade which could include slower operation of some phone functions and applications. Performance may be improved by limiting open applications.
2. Not all applications downloaded with your current software will be compatible with your upgraded software.
3. Media saved on your memory SD card will be preserved, but DRM (Digital Rights Management) protected Media stored on your phone's internal memory will not be preserved.
To update your Motorola Droid go to this official link now to download froyo firmware file to you computer.
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