Follow the steps below to learn how to encrypt your office documents!
To encrypt a file with password protection in Word, Excel, or PowerPoint, click the Microsoft Office button at the top-left corner of the Office program window. Select Prepare and then Encrypt Document.
Enter a strong password (at least eight characters, containing upper- and lowercase alpha characters, numbers, and symbols) into the Password field, and then retype the password when prompted.
Save the file in the Office 2007 format (.docx, .xlsx, or .pptx). While there is an option to save the file in the Office 97-2003 format (.doc, .xls, or .ppt), the encryption in that format is weak. The Office 2007 uses AES encryption, which is the current standard of the U.S. government.
Now when you or anyone else tries to open the document, a dialog box will open, prompting for the password.
To change the file encryption password, called the password to open in Office 2007, use the Tools in the Save As dialog box. Click the Office Logo button and select Save As. Then, in the Save As dialog box, click the file or enter its name in the "File name" field, click the down arrow beside Tools, and select General Options.
In the General Options dialog box, you can type a new password to open (the file encryption password) You’ll notice an option to set two passwords: one to encrypt and another to modify. Note that entering only a password to modify does not encrypt the document, it just prevents its modification by someone who wasn’t given the permission (i.e. the password) to do so.