Hi Everyone: I use boost 1.3.3.1 and stlport in my project,actually Boost::regex is my need. If I compile my project without include boost files in project settings,it's ok and of course cl told me that it can't find some header files such as regex.hpp . But if I add boost path into my project settings,the compiler will threw some erro just like below: BoostRegHandler.cpp D:\SyncSdk\include/stlport\cstddef(35) : fatal error C1001: INTERNAL COMPILER ERROR (compiler file 'msc1.cpp', line 1794) Please choose the Technical Support command on the Visual C++ Help menu, or open the Technical Support help file for more information Error executing cl.exe. I have no idea on this,does anyone compile your project with boost & stlport successfully? Or is there any seetings error of my project. BTW:I use vc6.0 , XP proffessional ,Intel P4 2.0 512 RAM Hongquan