Simply follow any of these procedures:

• Choose File -> Save.
• Click the Save   button on the Standard toolbar.
• Press Ctrl+S.
• Press Shift+F12.
• Press Alt+Shift+F2.

It is important to save a document periodically as you work. Having Word save it automatically will reduce the chance of losing data in case of a power failure or other interruption.

    1.    Select Tools -> Options... to open the Options dialog box.

    2.    On the Save tab, click the Save AutoRecover info every check box:

In the Minutes box, use the arrows to select a time or type a time for how often Word is to save your document.

    3.    Click OK to close the dialog box.