Probelmas en servidor remoto

[deprabado]

Ok, estoy empezando con esto del .NET y la verdad no se me da muy bie, he logrado hacer algunas cosas en mi PC local, el problema viene cuando subo la pagina .aspx y el .dll al servidor remoto.

Este es el error:

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.IO.FileNotFoundException: File or assembly name System, or one of its dependencies, was not found.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Assembly Load Trace: The following information can be helpful to determine why the assembly 'System' could not be loaded.

Localmente funciona perfecto, que estara pasando? me pueden ayudar? ya que de nada sirve poder hacer las paginas .NET y luego no funcionen en mi servidor.