Error : System.DllNotFoundExpection

[C# Programming]

hi guys , im using zeromq dll for making server/client program . the program works fine . but i want to run the setup of the program that i have made , in other computer with(win xp). it w'll throw an error

System.DllNotFoundExpection:Unable to load Dll 'libzmq':The specified procedure could not be found.(Exception from HRESULT:0x8007007F)
at ZeroMQ.Interop.zmq_init(Int32_threads)
at ZeroMQ.ZmqSocket..Ctor(int32 type,Nullable 1 context)
at ZeroMQ.ZmqDealerSocket..ctor()
at ChatClient.Client.Main(string[] args) in c:\my Development\ZeroMq\ZeroMQ_ChatTest\ChatClient\Client.cs:Line 13

but i have already attach the libzmq in the folder . so can any one tell me what's the problem ?
and sth more , it'll not throw an error if i run the setup on win 7 .