Changes
Added a warning because Windows is not a .NET delivery channel
<variable name="PKG_SOURCE" value="%SOFTWARE%\WMF\3\Windows6.1-KB2506143-x64.msu" os=".+6\.1\.\d{4}" architecture="x64"/>
<!-- dotnetfx4 will .NET 4 is also work sufficient. Note that if you're still using this far enough into the future that Windows does not include .NET 4 or 5 by default, you'll have to change the OS version regex. -->
<depends package-id="dotnetfx45" os=".+6\.[0-1]\.\d{4}"/>