Problem opening Outlook 2007. Came after adding on-line calendar.?

Hi. I have a computer running XP with office 2007. Everything had been working fine. I added a online calendar to my outlook. It was for concert schedules. Outlook still ran fine while I added the link for it to sync with, but now when I try opening outlook, it freezes or gives me the following error message, "The information service has not been configured. select an existing file to configure, or type name of new file to create". It then makes me create, or open a .pst file, but it won't work, and brings me straight back to that same error message no matter what I choose. I can not access anything in outlook once I get this error message. It just stays up. I can see my mail in the back round, but can't click it, nor can I click the toolbars in outlook. I tried uninstalling Outlook, and wiping the accounts free in the explorer, and reinstalling, but it did not solve the problem. Any ideas? Thanks a lot.

I installed iTunes, but it didn't help. Some more info though, sometimes when I try opening it, it says an outlook.ost file cannot be found. Also, on the left Outlook toolbar, there are about 15 personal files whereas before I only had one. Is there a place where Outlook saves the links and whatever else is needed for online calanders? Thanks!

try uninstalling itunes and see if it helps.