1.  Click Start, then Run, type Control Panel, and click the OK button. 

Or you could just click on the Control Panel icon in the Start Menu, if it is visible to you.

2.  Then scroll down in the Control Panel window, and click on the Security Center icon.

3.  Near the bottom of the Windows Security Center window, under the Manage security settings for: section, click on Automatic Updates.

4. Then click on the Turn off Automatic Updates radio button, and then click the OK button.

5. On the Resources sidebar, click on Change the way Security Center alerts me link.

6. Uncheck the Automatic Updates check box, and then on click the OK button.

Then close the Windows Security Center window, and the Control Panel window, and you are done turning off Automatic Update and the Windows Security Center Automatic Update notifications.