I am having a problem with the mex -setup command.

 I am having a problem with the mex -setup command in Windows 10.  When I type it in I get -

No supported compiler or SDK was found. You can install the freely available MinGW-w64 C/C++ compiler; see Install MinGW-w64 Compiler.

But I have installed the compiler. I suspect this is a path issue. How do fix ths.

[Jan]

Which compiler did you install? Did you check in the list of supported compilers, which ones are compatible with your Matlab version?

[Rik]

There is an issue buried deep in the notes that the Windows SDK 7.1 is not compatible with Windows 8 or 10.

About the MinGW compiler, did you install it from the file exchange? Did you try installing another supported compiler? (that link is for R2017a, link for older releases)