In Word 2010 , you can easily protect your word document by adding password it to so that only the users who know the password are authorized to open the document .
To apply password to protect a document from opening , follow these steps:
1. Open the word document.
2. Click File -> Save As. This should open the Save As Dialog .
3. Click the tools button and select the General Options from the combobox .
4. Enter the password in the Password to open textbox and click ok . This will ask you to confirm the password . Enter the same password again and click ok and then the Save button of the document .
5. Close the document and open it again . You will now be prompted for the password .