The difference between a Windows phone and an Android phone is that a Windows phone uses the Windows Operating System and an Android phone uses the Android Operating System. In my opinion, an Android phone is better because it has advanced features and is also popular among many mobile users.
The biggest difference between the two operating systems at this time is the number of available apps. There are many more apps available for the Android operating system than there are for Windows Phone.
Android is open source and is made by almost all phone manufacturers. There are currently 7 Android operating systems with Ice Cream Sandwich being the latest and currently waiting for the 8th, Jellybean. Most developers strive to create apps that work with 80% of Android phones. If you go high end this should not be a problem. Download apps from developers you trust and keep an antivirus installed on your Android phone.That being said a high security version of Android is being developed for U.S. Government use.
Windows Phone 7 live tiles instead of icons allow the user to find all their information quickly. The only customization available is pinning as many live tiles as you would like to your home screen that move and change to show you information or entertainment. All apps are listed in alphabetical order on the app screen and may be found by search, alphabet touch, or scrolling. Dedicated hardware makes for a very smooth and easy experience regardless of manufacturer.