OLMAPI32.dll is installed By outlook. But when you uninstall Outlook, it does not get removed. did you deleted OLMAPI32.dll file from C:\Program Files\ Microsoft Office\ Office 14 (sometimes it could be Office 12). If yes, then please try this.
Check and uninstall for any multiple or earlier version of Office installed on the computer.
Also make Outlook 2010 as not available. To do so do the following:
· Go to Start -> Control Panel -> Programs and features.
· Click on Microsoft Office 2010 and select change.
· Select Add or remove Programs and click on Next.
· Click on the symbol next to Microsoft Outlook and select Not Available.
· Click on Continue.
Once the custom uninstallation is completed, delete the MAPI/MSMAPI Folder from the following location: C:\Program Files \Common Files\System.
Also browse to the location C:\Program Files\Microsoft Office\Office14 and rename OLMAPI32.DLL to OLMAPI32.OLD.
Once the above steps have completed, make Outlook 2010 available and check if it helps. To do so do the following:
· Click on the symbol next to Microsoft Outlook and select Run from My Computer.
Source : microsoft.
Any more question please let me know.