Outlook 2003 with Windows 7

I had a new PC with Windows Vista (64-bit), loaded Outlook 2003 and it was working fine, albeit a little slow sometimes. I've now installed a 64-bit Windows 7 upgrade and can't get Outlook 2003 to work at all.
From everything I've read it seems as though there should be no major compatibility issue.
Any ideas?
Thanks in advance!:sarc:

We could probably help if you filled out your system specs for us.. otherwise we are just guessing.... Welcome to the forums...