I am working on with 5 workstations all running windows xp pro sp3 and 1 server running sbs 2003, one workstation is suddenly unable to open the address book in office 2003. When opening a new message window everything looks fine, clicking on the TO: button or the address book button will cause the "unable to complete operation. A fatal error has occured in outlook" message to show up. Outllook will generally remain running and useable but will sometimes just hang. I have already re-installed office, for another issue, excel was not opening but rather trying to install when launched, but thats already taken care of. I have also attempted using the detec and repair option and it trys to install office, anyone have any ideas on how to fix this?