When migrating a number of PC's from Office 2003 Professional to Office 2007 Enterprise, a number of users experienced problems whereby Outlook would constantly hang a few days after the upgrade had taken place.
1. How to Prevent Outlook From Hanging
<> Make sure that you uninstall the previous version of Office before installing Office 2007.
<> Ensure that hidden files & folders are being shown in Windows. Goto Control Panel - Folder Options - View tab to change this setting.
<> After Office is uninstalled - navigate to C:\Documents and Settings\\Application Data\Microsoft and rename the Outlook folder to 'Outlook.old' (or delete it if you don't fancy keeping a backup).
<> You should also rename/delete the Outlook folder found in C:\Documents and Settings\\Local Settings\Application Data\Microsoft
<> Restart the computer, then install Office 2007
<> If you didn't delete the Outlook folders but renamed them, you may wish to copy the Outlook.NK2 file to the newly created Outlook folder after you run Outlook 2007, as this file contains the AutoComplete email address history.
2. If Office 2007 is Already Installed and Outlook Hangs
<> Close Outlook and restart the computer
<> Logon as a different user that has Administrative rights
<> Rename the two Outlook folders (paths shown above). When you navigate to C:\Documents and Settings - go into the folder for the user that is having the issues - not your own admin folder that you are currently logged in as.
<> Log off and let the user log back in.
<> Start Outlook 2007. The Mail profile will be recreated and the emails will be downloaded (cached) again, if it is setup to do so.
The issue is caused on some computers when upgrading from Office 2003 to 2007. Some files in the Outlook folders become corrupted, causing the program to freeze. When you run MS Outlook 2007 in an Exchange environment for the first time on a computer - it is recommended that you do not use Outlook while it is 'Updating' all the email folders and calendars.