The Windows Azure Toolkit for Windows Phone is a must-have set of tools and templates making it easier for you to build mobile applications that leverage cloud services running in Windows Azure. It’s latest update is from November 2011, which makes it a bit difficult to install with the latest tools.
The root of the error is the Web Platform Installer tool, which is used by the WATWP setup program to check for dependencies.The documented system requirements are assuming you have Web Platform Installer 3.0 installed, instead of the current default, i.e. Web Platform Installer 4.0. Once you’ve uninstalled the 4.0 version and installed the old 3.0 version, the setup error should diminish.
Visual Studio 2010 Service Pack 1
You might receive the following error when installing Windows Phone SDk 7.1:
If the error occurs, you probably have not installed Visual Studio 2010 SP1 yet. You can do that from the Web Platform Installer. Once it’s installed, you can refresh the WATWP setup and continue it’s installation: