I’ve been using Microsoft Web Platform Installer for a while. It’s a great tool to install everything you need for web development, it installs SQL Server for you without bugging you with difficult questions. (on a side note: if you want to move your SQL DATA folder look at this post).
But there is a small problem when you launch the Web Platform Installer . It suggests you install Microsoft Visual Studio 2008 Web Developer Express Edition:
But when I check my Visual Studio:
It’s already installed.
Better file a bug on Connect 
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