Please remove the installation medium then press enter
The installation is asking you to remove whatever media (e.g. USB drive, CD, DVD, etc) that you used to boot the installer and then press the Enter key to reboot the machine.
This way it won't boot into the installer again.
If you have a virtual disk, this is the screen on which you click machine in the top left hand corner and then click storage. Then you have to choose the second option underneath storage devices, go to the right and look under attributes and uncheck the box that says 'Live CD/DVD'. I hope this helps!