Yitzchak Scott-Thoennes wrote: > void *dlh = dlopen("mydllalternate.dll", RTLD_NOW); That's because dlopen() is a Cygwin function that understands things like LD_LIBRARY_PATH and posix paths. But if you use it you are not using "the windows runtime loader", at least not directly. If you try your sample above using LoadLibrary it will fail. Brian