System Icons Description is not visible.

When I mouse over to the system icons, they usually show the description of the system icons.

For example, when I mouse over to the Wi-Fi icon, the connected wifi name would pop-up in a description box. or if I mouse over to the speaker, it would show 'sound' pop-up box.

It doesn't show any pop-up box now for every system icons except the notification icon.

How should I turn this on again?

chrismnpark said:

When I mouse over to the system icons, they usually show the description of the system icons.

For example, when I mouse over to the Wi-Fi icon, the connected wifi name would pop-up in a description box. or if I mouse over to the speaker, it would show 'sound' pop-up box.

It doesn't show any pop-up box now for every system icons except the notification icon.

How should I turn this on again?

Oh...my GOD....just rebooting showed this pop-up box again.