The builds tools for v120 (Platform Toolset = ‘v120’) cannot be found

If you have VS2013 installed and are getting this error, you may be invoking the wrong MSBuild. With VS2013, Microsoft now includes MSBuild as part of Visual Studio. See this Visual Studio blog posting for details.

In particular, note the new location of the binaries:

On 32-bit machines they can be found in: C:\Program
Files\MSBuild\12.0\bin

On 64-bit machines the 32-bit tools will be under: C:\Program Files
(x86)\MSBuild\12.0\bin

and the 64-bit tools under: C:\Program Files
(x86)\MSBuild\12.0\bin\amd64

The MSBuild in %WINDIR%\Microsoft.NET\Framework\ doesn’t seem to recognize the VS2013 (v120) platform toolset.