how can I post the data onto the server ?

If you are using a windows form, or console app, you will probably be best having a .NET remoted server process that will receive your data. Just create your server class, generalize MarshalByRefObject, and then have something register it with Remoting. Client side, reference the interface to your remote class and connect to it using your known 'name'' (see the doco for a more sensible description of this). If you are using a WebForm - you have a FileUpload control already available for you. Cheers,