Guys, after a few days browsing the web, ...here i am. Trying to compile ITpp on windows 7 64bits using mingw492_32 ( from Qt 5.5 distri). A few months ago it was working fine, not anymore. sh configure --enable-static --disable-shared -with-blas=blas --with-lapack=lapack --with-fft=fftw3 lapack and blas are found...looks liek it finds FFTW3 but not fftw3.h...but i added path to System path. ...any idea what's going on ? thanks, Output: configure:26046: result: no configure:26190: checking for zfft1dx...