with Microsoft Word. Or have to create one new file.

2. After opening or creating our file, lets click on file option, then select 'info'. 

3. Now click on 'Protect Document'. There will be few protecting option. Select 'Encrypt with Password'.

4. A new dialog box will be opened. Enter your password, click 'enter' then confirm Password by reentering.

That's how you can protect your document with password.

From now you will have to enter the password to open this document. To change or remove the password, open the document again. Follow the early steps, remove or enter new password and hit ok.

Before encrypting your document, remember one thing. If you lose or forget your password, Microsoft Word won't be able to recover it.  So, be sure to keep the  copy of the password in a safe place or create a strong password that you’ll remember.