i am doing such things ,and when i include winsock2.h,cvi hints that redeclaration in winsock2.h.later i use vc++6.0 to create a dll,int the functions i can use "Socket, SockAddr and others" because i include "winsock2.h",but in cvi i do not use them.Now cvi can call the functions in the lib generated from the dll using the "Options\Generate Dll Import Library",but the value returned alwsays is 10038(in vc++ Error Codes ,you can find it refer to "WSAENOTSOCk").who can help me with the question?