“Notifications” is the section of PC Settings where you come to configure all the notification-related settings for Metro apps.
How to Access It ■ Invoke Settings Charm either through
the Charms Bar or key combo “
Win + I”.
■ Select “Change PC Settings” option located at the bottom of
the Settings Charm pane. This will launch PC Settings.
■ Select “Notifications” tab from the left pane of PC Settings.
Notifications SectionThe general notification settings include the following.
■ You can specify whether or not you want to see any notification at all.
■ You can enable/disable notifications on the lock screen. This will remove all the widgets from the lock screen leaving only date, time and the wallpaper.
■ Set whether or not the notifications should arrive with sound.
Besides that, you can toggle notifications from an individual application. If you don’t want to hear from a specific application, you can simply turn the notifications off for that app.
As shown in the above image, I have turned off notifications from Music; I know, after all, what song I am listening to!
Also, I have disabled annoying notifications from Messaging and from Internet Explorer.
source:windows8update