Once you get the access to the Guest Desktop Environment.
Now before you start the lab you first need to restart GNS3-VM.
Click on "Restart GNS3-VM" bookmark
After that, you will get the following screen with a countdown timer. Please be patient and wait for the timer to expire. (Do not reload the page)
After the timer expires, following screen will appear. It means that you have successfully restarted GNS3-VM.
Run GNS3 as administrator as shown below
Create new project
Drag and Drop devices from menu
Click on start button to start all devices
Click on console button to launch console of all devices
Configure the devices
Click on stop button to stop all devices