Transfering P3 Files from 1 Computer to Another Help

Hi

How do I transfer my P3 Files on my laptop to my computer?
Is it Possible?

Every time I copy the folder with all the P3 files on my
laptop to my Computer hard disk P3 Root Folder in c drive, I always get a message saying "Target Project Not Found" when opening the file I just transferred.
Where do I find the actual Path of the P3 file which needs to be opened? Such as when you open a word file you open the extension saying .doc. What is the extension I need to copy to the hard drive so the file can open?

Thanks