Outlook 2003 and GPG

I recently installed gpg4win 2.1.0 on a machine running Windows XP Pro and Outlook 2003. This resulted in Outlook not being able to start up, as it seemed to be looking for a server like Exchange. After closing Outlook, it would not re-start, and I had to uninstall GPG and re-boot twice to recover. I’d love to make this work, and it seems I’m missing something somewhere. Any input?