I don't want to crawl/show Document content for Sharepoint search

I have a Sharepoint Document repository site, but when I am typing anything on the Search box, not only it searches for Files and Folders it also searches the document content and returns the documents, I don't want this as I have too many documents and the search results are getting very confusing. I did a Reset Index and then a full crawl but nothing helped.Please suggest how to exclude document content from the search sources.