The default time interval for notifications that pop up in Windows 8 is five seconds. This means that these notifications will be visible for five seconds. However this time period can be changed as needed.
Here is how to do this :
1. Access the Settings function from Windows 8 charm bar and choose “Change PC settings”.
2. From the “Ease of Access” column, change the value under “Show notifications for” to any of the listed time interval as needed.
All done. From now on, the notifications that are displayed will stay for the specific time delay.