You can use the Inspect Document feature to find and remove hidden data and personal information in Word documents. It is a good idea to use the Document Inspector if you share documents or upload them to the web or Blackboard.

As a precautionary measure, always create a backup copy of your document before using the Inspect Document Inspector.

Open the Word document
Click Office Button / Go to Prepare
Select Inspect Document

Click Inspect Document; the following dialog box will open with options

Select the options and Click Inspect button
The inspection results will display
Click Remove All

I always Reinspect the document for security purposes.
 

Word documents can contain the following types of hidden data and personal information:

• Comments, revision marks from tracked changes, versions, etc. If you collaborated with other people to create your document, your document might contain items such as revision marks from tracked changes, comments, or versions. This information can enable other people to see the names of people who worked on your document, comments from reviewers, and changes that were made to your document.
• Document properties and personal information  Document properties include details about your document such as author, subject, and title. Document properties also include information that is automatically maintained by Office programs, such as the name of the person who most recently saved a document and the date when a document was created. 
• Headers, footers, and watermarks  Word documents can contain information in headers and footers. Additionally, you might have added a watermark to your Word document.
• Hidden text  Word documents can contain text that is formatted as hidden text. If you do not know whether your document contains hidden text, you can use the Document Inspector to search for it.
• Document server properties  If your document was saved to a location on a document management server, such as a Document Workspace site or a library based on Microsoft Windows SharePoint Services, the document might contain additional document properties or information related to this server location.
• Custom XML data  Documents can contain custom XML data that is not visible in the document itself. The Document Inspector can find and remove this XML data.