So the trick is know your resolution of your monitor. Then at the botttom below your taskbar in the middle it hides the virtual task bar for switching settings. Then if you want to put it in full screen you can. Once you get used to how this works you won’t do it any other way because this works the best 99.9% of the time.

So here is the way i do it most of the time. The problem with trying to set the resolution after the fact is that sometimes it just reverts back whether you set it in the installed system from display or the welcome app. So the actual resolution is 1680x932 as shown by the tool in the welcome screen. V-box will auto adjust to the size needed which is slightly smaller to fit in the window allowing my host task bar to be accessible. So as you can see here by the picture i have kde running in vm on v-box on kde as the host and the resolution i set the same as my monitor which is 1680x1050.

So I have KDE installed in virtual-box and I’m running it on EndeavourOS KDE as the host.

I don’t normally run virtualbox in full screen mode. The trick is with virtualbox normally is to set the resolution the same as your monitor and it will auto adjust when it loads to the proper sizing to fit the window leaving your Host task bar viewable. It never used to work properly before but now does for most installs. There are numerous settings for the graphics controller under display.

How to make my virtualbox full screen