Brand new Lenovo Yoga 1 TB ssd
Successfully installed Debian 6.1.76-1 (bookworm)
Speed bump there. The NetInstall wanted to know my WLAN chipset. I guessed Intel correctly, and Life is Good.
Successfully installed Virtualbox 7.0.14
Successfully installed Virtualbox Extension Package
Successfully installed Windows 11.

The resulting display is only 1/3 of the available window size. Display memory allocation is apparently maxed.
How do I increase the display size?

You can use the view pull down menu to adjust the size/scale but you should install guest additions which will allow you to resize the window on the fly.

yes, if I remember well virtualbox has a default display size, which is relatively small.
https://forums.virtualbox.org/viewtopic.php?t=106945

1 members found this post helpful.

Thank you.
The Virtualbox display is fine. It fills the entire screen. It is the Windows display that is 1/3 of the VB display.
The Oracle web page for Guest Additions does not list support past Windows 10, and I have Windows 11. We will see what I can achieve after I get Additions added.

https://docs.oracle.com/en/virtualiz...estadd-install
win11 is suppported

Basically the size of the "Windows" display is controlled by the settings in the view pull down menu and not necessarily the size of the VirtualBox guest window. With guest additions you can resize the virtual machine window and the video resolution will be automatically adjusted.

https://www.virtualbox.org/manual/ch...-resize-window

I would expect guest additions to work with Windows 11.

I finally found the correct version of Guest Additions: VBoxGuestAddions_7.0.14.iso
That matches the version of the VirtualBox iso.
Put that on an optical disk.
Started VirtualBox and then Windows.
selected VirtualBox Tools, and ADD, then Optical Drive. VBoxGuestAdditions_7.0.14.iso appeared.
Selected that, the optical disk spun up, and nothing else happened.

In the Windows file browser navigate to the optical drive d: or whatever and run the program VBoxWindowsAdditions.exe

Again, VBoxWindowsAdditions.exe should be executed inside the VM, not on the host. You need to find this virtual CD in it, and you need to look for that exe on that drive. On windows sometimes it can be started automatically, when you "insert" this virtual disk (iso file) into that virtual CD reader of the VM. But first you need to have a CD reader in your VM. There is no need to have a real optical disk, you cannot insert it into a [virtual] CD reader of a VM.

As per my previous post, I attempted to "add" VBoxGuestAddions_7.0.14.iso to the Virtualbox. Nothing happened. I downloaded the iso, burned it onto an optical disk, and loaded the USB-DVD reader on the laptop. VirtualBox does recognize that drive + iso.
There is no *.exe file to be found within that iso, and I have not been able to locate a VBoxGuestAdditions*.exe anywhere.

Running from a USB optical drive should work but not necessary. Did you just burn the ISO file to disk or did you select burn as image?

Since you have the ISO file, from the guest's window menu (hopefully it is visible) select Devices -> Optical Drives -> Choose a disk file, then navigate to the location and select the ISO file in the directory window. Then select in the Windows file browser the CD drive ( d: or whatever). The contents of guests additions ISO file is the following. I always select VBoxWindowsAdditions.exe which should select the proper version i.e x86 or amd64.

From your posting, I should be able to open the folder "NT3x" and run the *-X86.exe file. No joy. Virtualbox will open the ISO and display
(Note: There is no autorun file/folder).
However, when I click on "NT3x", I get a blank window. I.e. there is no .exe file present.
??

I do not know what you mean by VirtualBox will open the ISO?
Did you attach the USB drive to the Windows VM? From the windows pull down menu select devices -> USB and then select the USB drive. In the Windows file browser you should have a device ID for the drive E: or whatever. That is where you should see the contents of the guest additions disk.

If you inserted the guest additions CD image from the VM devices pull down menu the contents should be available in the Windows file browser in the virtual CD drive maybe D:

I think you are trying to the add the ISO by selecting the cd drive from VB file manager not Windows. I am guessing there is a file filter being applied for ISO extension so no files seen.