Outlook won't start after changing the data file to ICloud

Hi,

I can't start Outlook 7 after installing Icloud on my Dell Laptop. After installing the icloud control panel I changed the data file in Outlook to Icloud as instructed on a online video instruction. The Calender and contacts got transfered to my IPhone and Ipad, but after closing down outlook I can't stat the program up again. I get the error "Cannot start Microsoft Office Outlook. Cannot open the Outlook Window. The set of folders cannot be opened. Unknown error.

Please Help.