I do remember this error message in a very long and complicated thread Why do I get this error everytime I try to build the new marlin firmware - #13 by NormanDunbar.
As a quick test, can you install http://mingw-w64.org/doku.php/download/mingw-builds and add it to your PATH so that gcc is executable from the commandline (ref)? Reboot your PC after that and retry compilation.
Another cause could be an outtdated Marlin version.