The installation of the Google Apps Sync plugin disables Outlook’s ability to search any and all of your Outlook data,” stated Dev Balasubramanian. “When a Google Apps user installs the sync plugin for Outlook, the plugin modifies a registry key which disables Windows Desktop Search from indexing and providing search functionality for all Outlook data, not just the Outlook data being synchronized from GMail. Because Outlook search relies upon the indexing performed by Windows Desktop Search, Outlook search functions are broken as a result.” To resolve: Browse following: "HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search" — then Right click on “PreventIndexingOutlook” key, select “Modify…”, then change the value data to “0” (without the quotes).