I tried to build boost thread library on my computer,the following are my computer's configuration: stlport-4.5.3+boost-1.30.0+msvc6(sp5)+platform sdk(5.2.3663.0) I added boost installation directory into system's path variables, and i enter into the directory "boost_1_30_0\libs\thread\build\",Each time i typed command "bjam -sTOOLS=msvc-stlport -sSTLPORT_VERSION=4. 5.3 -sSTLPORT_PATH=D: -sSTLPORT_IOSTREAM=on >>d:\log1.txt", i got the following result: CALL "C:\Program Files\Microsoft Visual Studio\VC98 \bin\VCVARS32.BAT" >nul "C:\Program Files\Microsoft Visual Studio\VC98\bin\cl" /Zm800 - nologo -GX -c -DBOOST_THREAD_BUILD_DLL=1 -D_STLP_NO_SGI_IOSTREAMS=1 - D_STLP_DO_IMPORT_CSTD_FUNCTIONS=1 -D_STLP_DEBUG=1 - D_STLP_DEBUG_UNINITIALIZED=1 /Z7 /Od /Ob0 /GX /GR /MDd - I"..\..\..\libs\thread\build" -I"D:\STLport-4.5.3\stlport" - I"D:\boost_1_30_0" - Fo"..\..\..\libs\thread\build\bin\boost_thread.dll\msvc- stlport\debug\runtime-link-dynamic\stlport-cstd-namespace-std\stlport- iostream-off\stlport-version-4.5.3\threading-multi\condition.obj" - Tp"../src\condition.cpp" ...failed vc-C++ ..\..\..\libs\thread\build\bin\boost_thread.dll\msvc- stlport\debug\runtime-link-dynamic\stlport-cstd-namespace-std\stlport- iostream-off\stlport-version-4.5.3\threading-multi\condition.obj... It seems some configuration problem exists. Can anybody tell me why? Thanks in advance!