May be, this example will help you. Sorry i have no time to explain what does it mean. I hope, you will get it ..... STARTUPINFO si={0}; si.cb = sizeof(si); si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES; si.wShowWindow = SW_HIDE; <<-------- Here we hide window si.hStdOutput = hWrite; si.hStdError = hWrite; PROCESS_INFORMATION pi; CreateProcess (szCompilerName,szCommandLine, NULL,NULL,true,NORMAL_PRIORITY_CLASS,NULL,NULL,&si,&pi)