You cannot/should not, it appears, retain Outlook 2007 installed on your PC after upgrading to Outlook 2010.
If, as I did, you do not de-install Outlook 2007 after the upgrade you may find that you cannot run Outlook 2010. In such case you may get the following error message when attempting to run it:
“The file OLMAPI32.dll is incompatible with Microsoft Outlook. Install Outlook again”
It may be possible that had I uninstalled Outlook 2007 or had I never attempted to run Outlook 2007 after upgrading to Outlook 2010, this error may never have appeared. Nonetheless, once this error appeared I was not able to run Outlook 2010 again until I uninstalled Outlook 2007 as described below.
Note: As always, before proceeding, I recommend creating a restore point in case something goes wrong.
According to this Microsoft Answers post, the solution did not lie in ”Installing Outlook again’ as the error message suggested. Rather, the solution required uninstalling Outlook 2007 and repairing Outlook 2010.
So, off to Add-Remove Programs from the Control Panel to Remove Outlook 2007 right? Not so easy.
