Scenario: You set up a Search Service Application in SharePoint 2010. You configure your content sources to crawl your sites. You notice that documents that were created using Word 2007 are not searchable based on their Title. The search crawler picks up the first few words in the document, but not the Title.
Impact: One of the consequences of this issue is that the quality of your search results will be significantly reduced, especially if many of your documents begin with text that is the same or very similar to every other document (e.g. disclaimers). Because the title is not being crawled for Word 2007 documents, all of the documents with similar beginning text will appear in the search results for any given query, and it will be difficult to distinguish them.
Solution: The fix for this issue consists in editing the registry on the server that is running the search service application.
Open registry for editing by typing “regedit.exe” in Start > Run
Navigate to the key [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office Server\14.0\Search\Global\Gathering Manager]
Change the hexadecimal value for EnableOptimisticTitleOverride to 0 (zero) on the right hand side.
Restart SharePoint Search service by typing the following commands in command prompt.
net stop osearch14
net start osearch14
Perform a full crawl
Once the crawl in completed you will be able to search for documents based on their title.