How do I merge 2 copies from 2 machines?

I have had to build a new system for windows 7. I would like now to merge (from my old disk) the data of my old em client. Is this possible, and if so, how do I do it?

On your old PC, export the e-mails to .eml files, and contacts to vCard and calendars to iCal. (make sure there’re no duplicate entries between your new and old system, unless you want to be this way)

Simply import these files on to your new PC and you’re done.