Solution to olmapi32.dll Not Compatible Error

Olmapi32.dll is an Outlook MAPI32 program file and is required for the smooth functioning of Outlook, a popular email application from Microsoft.


You may encounter the following error when you try to start Outlook 2007.

“The file OLMAPI32.DLL is incompatible with Microsoft Outlook. Install Outlook again".


To resolve the olmapi32.dll not compatible error, you may use any of the solutions mentioned below-

Solution 1

  1. Click Start.
  2. Click Control Panel.
  3. Double-click Add or Remove Programs.
  4. Select Office 2007 in the currently installed programs list, and then click the Change button.
  5. Select Add/Remove Features.
  6. Click Continue.
  7. Click on the first option and select Run All on My Computer.
  8. Follow the onscreen instructions to complete the installation process.

Solution 2

  1. Close all open applications.
  2. Restart Windows in Safe Mode.
  3. Use the built-in search utility to look for msmapi32.dll.
  4. Right-click msmapi32.dll, click rename, type msmapi32.old, and then press Enter to rename the file.
  5. Install Outlook 2003.

Solution 3

  1. Install Windows Installer Cleanup Utility.
  2. Click Start>All Programs>Windows Install Clean Up.
  3. Locate and remove all entries related to Office 2007.
  4. Reinstall Office 2007.

If reinstallation fails, then you need to perform the following additional steps:

  1. Log on to your computer as an administrator.
  2. Click Start>Run.
  3. In the open box type msiexec.exe /unregister and then press Enter.
  4. Double-click the My Computer icon on your desktop.
  5. Click Tools>Folder Options.
  6. Click the View tab in the Folder Options dialog box.
  7. Uncheck Hide extensions for known file types and Hide protected operating system files (Recommended).
  8. Click the OK button to save your preferences.
  9. Open Windows Explorer.
  10. Open the C:\Windows\System32\dllcache folder.
  11. Here, rename the following files:
  12. msihnd.dll to msihnd.old
  13. msiexec.exe to msiexec.old
  14. msi.dll to msi.old
  15. Download the latest version of the Windows Installer Cleanup Utility and run its setup.
  16. Reinstall 2007.

Solution 4

Note: The steps discussed below require you to edit the registry. It is essential that you make a registry backup before editing it. You may use a reliable registry maintenance software for this purpose or back up the registry manually.

  1. Exit Outlook 2007.
  2. Click Start>Run.
  3. Type regedit in the Open box and then press Enter.
  4. In the registry editor window, click Edit>Find.
  5. Type olmapi32.dll in the ‘Find What’ box, and then click Find Next.
  6. Locate and click HKEY_CLASSES_ROOT\Installer\Components\613B99D5CFD 7FCB4793B500086BB4113 (Note: the last string of numbers may vary). If you don’t see the entry the first time, continue to press F3 until you locate an entry same/similar to the one shown above.
  7. Locate and select olmapi32.dll in the right-pane of the registry editor window, and then click Delete.
  8. Close Registry Editor.
  9. Open Outlook 2007.