With many applications being used, there can be many notifications generated for each of them in Windows 8.1.
However, the “quiet hours” settings can be used to turn these notifications off for a desired time interval.
To do this :
Access the PC settings using the Windows 8.1 charms bar an go to “Search and apps”.
From the “Notifications” column, make sure that “Quiet hours” slider is turned on and then change the time interval for which all the notifications need to be disabled.
These notifications will then no longer be displayed for that time period provided that the PC isn’t in use then.
Cheers.