Does anyone know where I can get the MCADUSER.LIB file? I found one on some dll that someone else wrote years ago... I think that this is why some of my properties (from REFPROP) are not being called. The file is supposed to be in the LIB folder in Program Files\Mathcad\Mathcad 14\userefi\microsft But I am missing the LIB folder all together. Thank you in advance. Carlos Herrera