Linux Mint won't fit into VirtualBox window (Windows 7). How can I remove the scrollbars so that the Linux Mint window fits completely into the VirtualBox window?

Question

linux

I'm running VirtualBox (on Windows 7) with Linux Mint installed and I see scrollbars like this. Those. Linux Mint won't fit into the VirtualBox window.

Tried (in VirtualBox menu)

Устройство - Подключить образ диска дополнительной гостевой ОС

and (in terminal)

sudo apt-get install virtualbox-guest-additions-iso virtualbox-guest-dkms virtualbox-guest-x11 virtualbox-guest-utils

Did not help.
How to fix?
PS
When I installed it, I had to select " Start in compatibility mode " in the BootCD window. could not install in normal mode (tried 2 times on a working PC and a home laptop) - the installation did not complete until the end (it gave an error).

Answer 1

Changed the size of the hard disk (in VirtualBox) to 25 GB and reinstalled Linux Mint (in normal mode, not compatibility mode ) - the problem disappeared.
Even without installing "additional guest OS disk image" - no sliders and everything works great!

Answer 2

virtualboxes.org/doc/installing-guest-additions-on...
Start from step 5

Answer 3

Until the guest software is installed, this window will remain. Here is the step by step:
www.tomshardware.co.uk/faq/id-1957309/install-virt...

Answer 4

You can also adjust the screen resolution.