I've installed Windows 8, Visual Studio 2012 but don't have a v4.5 directory in %WINDIR%\Microsoft.NET\Framework
.
Have I done something wrong, or is .NET 4.5 different from others?
If it's because I have not installed the tools, is there a set of different tools to download? As far as I can tell, I am able to build .NET 4.5 apps OK.
.NET 4.5 is an in place replacement for 4.0 - you will find the assemblies in the 4.0 directory.
See the blogs by Rick Strahl and Scott Hanselman on this topic.
You can also find the specific versions in:
C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework