Update launch exercise button image

Author: Rob-Barefoot

learn-pr/wwl-azure/describe-azure-compute-networking-services/includes/9-exercise-configure-network-access.md

@@ -5,4 +5,4 @@ Launch the exercise and follow the instructions.
 > [!NOTE]
 > You'll need access to a Microsoft Azure subscription to complete this exercise.
 
-[![Button to launch exercise.](../media/launch-exercise.png)](https://microsoftlearning.github.io/AZ-900-Microsoft-Azure-Fundamentals/Instructions/Labs/03-exercise-create-azure-virtual-machine.html)
+[![Button to launch exercise.](../media/launch-exercise-button.png)](https://microsoftlearning.github.io/AZ-900-Microsoft-Azure-Fundamentals/Instructions/Labs/03-exercise-create-azure-virtual-machine.html)