CRM2013 installation

Hi All ,


thanks to help me , i'm trying to install the CRM 2013  for the first time , the Server is ready , however i'm facing a very weird error 


"Could not load file or assembly 'Microsoft.CRM.setup.Interop, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. An attempt was made to load a program with an incorrect format"


Does anyone have an idea what is wrong or how to solve this error