Outlook XP

I was using XP office and than upgraded to Office 2007. I did not like it and reinstalled XP Office. Everything works just fine except Outlook. it does not open and I cannot access my address book which is essential to me. I reinstalled and the same problem ocured. It states ” unable to open your default e-mail folders. Could not open the item, try again.” If I click OK it asks me “Would you like to open your default file system folder instead?”
I click yes and it takes me to MY COMPUTER – MICROSOFT OUTLOOK with a drop down list but not my to me familiar window where I can look at my addresses and appointments.
Anybody knows what I did wrong here? Please tell as I really need my addresses.
Thanks,
Gernot