How to Hide the Joomla Post-installation message
After installing Joomla 3 and logging into the administrator control panel, you may see the Joomla post-installation message …
There is no X button to dismiss it. Only the “Review Message” button. But even after you click the “Review Message” button, the message is still there.
Even after you log out and log back in, the message is still there.
What you have to do to hide this message is to click “Review Message” to read it …
After each of message, there is a gray “Hide this message” button. You have to click this button for each of the messages.
You will get a confirmation page saying no more message …
But don’t click the orange “Reset Message” button, otherwise the post-installation message box will appear again.
After hiding the messages, you can always bring them back by going to …
“Components -> Post Installation Messages”
and then clicking the “Reset Messages” button.