Migrating Email Between Computers

This has to be a common problem, but I cannot seem to solve it. I have a desktop and a laptop.

I want to migrate my emails from the desktop to the laptop without losing any of the emails already on the laptop.

Both are running Outlook 2003.

The desktop has Windows 2000.

The laptop has Windows XP.

I know how to backup Outlook to a .pst file and copy this from one computer to another, but this REPLACES the .pst file, and thus, loses all the emails already in the.pst file being overwritten.

Export/Import does not work (at least I cannot seem to make it work for me). I get an error message that says I cannot import to the same folder.

I can’t believe, that after all this time, Outlook does not have a simple way to handle this.