Password

With NTFS you can choose which users can use folders, but you can't set passwords.
Look at
http://www.winability.com/home/

In MS Word, you can password protect documents:

1) Open the document.
2) On the File menu, click Save As.
3) On the Tools menu in the Save As dialog box, click General Options.
4) In the Password to open box, type a password, and then click OK.
5) In the Reenter password to open box, type the password again, and then click OK.
6) Click Save.

Or you may require a user to enter a password to modify a document:

1) Open the document.
2) On the File menu, click Save As.
3) On the Tools menu in the Save As dialog box, click General Options.
4) In the Password to modify box, type a password, and then click OK.
5) In the Reenter password to modify box, type the password again, and then click OK.
6) Click Save.