No wide screen in Linuxmint LMDE in VirtualBox VM Oracle

[recognition]

Hi,
When I run linuxmint lmde in Virtualbox, a message is displayed that the graphics is not maximized, and there is no display of the entire screen, even though the virtual machine is displayed on the full screen. What should be set in the virtual machine settings to have a full view? The processor is duo with 4Gb memory.
The Gusest Addition is already marked in the Virtualbox:
Settings -> User Interface -> Devices -> Insert Gusest Addition CD Image
(Marked with v).
Hard Disks is not marked, but I run linuxmint lmde on live.
Thanks to the responders.

[Monsta]

Having the guest additions CD image inserted isn't enough - you need to install the actual guest additions from it.

[recognition]

Hi, I did not succeed to install the guest addition.
Trying to install it from the terminal by "sudo apt-get install virtualbox-guest-additions-iso" – removed the virtualbox as well as libcurl3 (a dependency of virtualbox).
Trying to reinstall the virtualbox (v 5.2.18), telling it had conflicts with the guest addition (v 5.1.38), and I had to remove the guest addition.
Trying to install the guest addition directly from the virtualbox, displays:
"Unable to insert the virtual optical disk /usr/share/virtualbox/VBoxGuestAdditions.iso into the machine Lmde3" (the name which I gave to it).
VERR_PDM_MEDIA_LOCKED
https://superuser.com/questions/760327/ ... dia-locked

[srq2625]

Search engines can be your friend - first couple of entries from this seach provide a step-by-step on installing the guest additions.

HTH

[recognition]

Linuxmint LMDE was running live in the virtualbox.
It was the reason why there was no room for the Guest Addtion CD. It was locked because the virtualbox used the CD for running Linuxmint LMDE itself.
One solution is to fully install Linuxmint LMDE in the virtualbox, and free the CD afterwards.
Another solution is to add a second CD for the Guest Addtion image. Is it possible to add a second CD, or an usb input?

[Monsta]

Ah, I missed the live part. Ok, then adding another virtual CD/DVD device could be a solution. It's possible to do in the VM settings.