why cant mex find visual studio 2013

Have MATLAB R2015a, and Visual Studio 2013 Professional installed on Windows 7. When I run "mex -setup -v" I get the "Did not find installed compiler 'Microsoft Visual C++ 2013 Professional (C)" message even though it seems to have found at least some of the things it was looking for:

... Looking for compiler 'Microsoft Visual C++ 2013 Professional (C)' ...
... Looking for registry setting 'HKLM\SOFTWARE\Microsoft\VisualStudio\SxS\VS7' 12.0 ...No.
... Looking for registry setting 'HKCU\SOFTWARE\Microsoft\VisualStudio\SxS\VS7' 12.0 ...No.
... Looking for registry setting 'HKLM\SOFTWARE\Wow6432Node\Microsoft\VisualStudio\SxS\VS7' 12.0 ...Yes ('C:\Program Files (x86)\Microsoft Visual Studio 12.0\').
... Looking for file 'C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\amd64\cl.exe' ...Yes.
... Looking for folder 'C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC' ...Yes.
Did not find installed compiler 'Microsoft Visual C++ 2013 Professional (C)'.

What is it missing?

Answer 1

[Eric]

Apparently it's missing entries in your Windows registry. You could double-check that those entries are missing using regedit. If they are indeed missing, you might look at https://stackoverflow.com/questions/24189700/missing-registry-hklm-software-microsoft-visualstudio-sxs-vs7 for a couple suggestions on how to fix this, one of which is to re-install VS.