I have tried compiled boost::thread for windows using visual c++ from the visual studio .net 2003 suite. It compiles fine and I can compile things with the created libraries. However, when I move my program and the boost::thread dll:s from windows 2000 to another machine running windows XP, the program just prints out a blank line and exits without any other message. Attached is a program I have used to test out that it is this that is wrong. What have I done wrong? Is it impossible to compile the boost libraries on windows 2000 and then expect the created dll:s to work on windows XP? If this is the case, where can I get hold of the boost::thread libraries for vc71 compiled specifically for windows XP? If not, what could be wrong? /Ragnar Ouchterlony