I have bought a new computer which has Outlook 2007. My previous computer
uses Outlook 2003. I would like to keep and possibly 'transfer' the old
(stored) emails from my previous computer onto my new computer so that if
need be, I can view them again.

Where should I look in the 2003 version and which file should I copy?

I think I recall being told several years ago that Outlook stores Contacts
in a file ending with .pst but I am not sure about the extension of the file
which stores the emails. I do not necessarily want to replace my current
(Outlook 2007) emails and folders with the previous version, I simply want
to know that they are on my new computer and I can view them when I want
(when I learn how to)

TIA