Thank you guys. The program in VC++ works well in windows OS. Many people are using it for several years. I have changed anything related to MFC, then compiled and built it in C::B IDE, no warning and no error. When I clicked "RUN" botton on tool bar of C::B IDE, several seconds later the program terminated without error, but the output was not correct. I debugged it step by step, the output was correct. It is that I said "works in debug mode, does not in release". Thanks again.