If you are tired of the constant, not very helpful, security notifications in Windows Vista, you can adjust them so that they are less annoying, and you can turn them off entirely.

To do so, open the Control Panel and select Security Center. Once the security center panel is shown, select the link labeled "Change the way Security Center alerts me". This will open up a window that allows you to remove the messages that are shown while keeping the icons, or to turn off the messages completely.