How can I back up Outlook emails individually, not via .pst.

I have thousands of emails, lots of which I need to refer to regularly. (Real estate oriented.) I have the pst backed up but I would prefer to have the emails viewable on my back up drive so that I can see them from multiple laptops whenever I need them.

So, I need to move/copy email from Outlook to an external drive so that I can read them individually easily and quickly.

Can I install a copy of Outlook on the backup drive? Not to run to retrieve mail, just to facilitate reading the old mail? Does it matter that there’s no OS on it?

Using Outlook 2003 and XP. Thanks!