Hi,
have you tryed with other user account?if this is a problem on every PC/evry user account then something is wrong on server side.otherwise i recommand doing the following steps:
1).try starting outlook in safe mode
go to run--->outlook /safe
2).make sure you close the outlook and delete the outcmd.dat from c:\documents and settings\<username or username.domainname(if the user is on domain)>\application data\microsoft\outlook and then restart the outlook
3).other reason might be a background service is running, check the CPU usage when you start outlook
4).try using ad aware to remove any spyware
5).after all put the Outlook CD in and do a reapir.
i hope it should solve the problem.
regards
REDDY