You can fix this problem by rebuilding the search catalog. To do this, exit outlook first and open the Windows control panel. Identify and click on Indexing Options. When the Indexing options dialog box opens, click on Advanced if you are unable to search on Outlook. A new dialog box will open named Advanced Options; you must find and click on the Rebuild option. Finally, click OK and then close the box. If this process does not work, kindly uninstall and reinstall Office.