I have installed mingw32 on 64 bit Windows 7 using mingw-get-inst-20110530.exe I have been referred to http://sourceforge.net/projects/gmpmingw/ for a mingw32 binary version of GMP.  I have the following in my etc/profile file: export PATH="/home/User/nano":$PATH; export PATH="/home/User/":$PATH; export PATH="/home/User/gmp-5.0.2":$PATH; I need to get the following working: GMP MPFR MPC I am finding now that "C preprocessor /lib/cpp is failing a sanity check." when I attempt to compile MPFR, with the aforementioned binary GMP. Are there any mingw32 people who know what I need to do to my /lib/cpp to get it behaving better? The advice I have so far doesn't help; further complicated that I seem to have a working /bin/cpp already. What changes do I need to introduce?