Hi,Now with these flags in the .pro file
INCLUDEPATH +=C:\boost_1_49_0\boost_1_49_0LIBS +=-LC:\boost_1_49_0\boost_1_49_0\stage\lib -lboost_thread-mgw44-mt-1_49 I get a linker error collect2:ld returned 1 exit status I have built boost thread with bjam --toolset=gccstage --with-thread and it has build a .a file in release and debug folders. What is preventing the linker? Thanks Jothy