Told to use Disk Utility, Cannot find a "Tools" or "Utilities" menu

[LuigiWriter]

This is the latest Virtual Box on the latest Ubuntu. I created my first VM but had an ISO of Win 10 64-bit, but this is a 32-bit computer. closed the VM and downloaded an ISO of Win 10 32-bit and created a new DVD.
The DVD is in the optical drive and recognized by Files and open-able.
in VirtualBox SATA port 1 is [Optical Drive] host drive hp DVD RAM [sr0].
Open the VM and get "no bootable medium found"
Have searched and read the manual, help and the forum until my eyes are ready to fall out. See mentioned use Disk Utility on the Utilities Menu. Another says it is on the Tools Menu.
With the VM in this state the menu only has "File Machine View" and the Manager top menu only has "File Machine Help" None of the drop down menus contain a Utilities, Tools or Disk Utility entry.
How do I get to Disk Utility
Help has no instruction on how to get back to the First Start Wizard which seems the only place one can specify a installation medium. Searching for that topic yielded no results so I am stuck and confused.

[Perryg]

I can't comment on the points you raise while searching, but I can tell you that the settings in the main manager has a section that is called storage and from there you can control this very thing.

[LuigiWriter]

Did as you suggested.
In Main Manager>Settings> Storage > Controller SATA
Already listed
* win 10 32-bit.vdi
* VBoxGuestAdditions.iso [which are installed [File>Preferences>Extensions]]
Chose add new optical disk to controller SATA ]
"Would you like to choose a virtual optical disk to put in the drive or to leave it empty for now?"
[Is "virtual" the same as the internal hardware optical drive I am trying to connect?]
selected [Choose disk] not [Leave Empty]
In Please choose a virtual optical disk file, I selected the internal optical disk labeled ESD_ISO [only one available]
Found listed the files boot, efi, sources and support. and in root and all sub-folders:
* no "virtual optical disk files" listed
* no DMG files listed
* no RAW files listed.
Of all files, no ISO extension file listed. [see screenshot 1]
This disk was created using the Microsoft Media creation utility by selecting "Create a disk for another PC" has booted in this machine and loaded select language and the Install windows pages. I did not go further because this is an Ubuntu OS computer and I did not want Microsoft to replace it with windows 10.
My only choices at the choose a virtual optical disk file window are [Cancel] and [Open]
I couldn't find an .iso file so tried autorun.inf and setup.exe. [see screenshot 2]
No way of choosing the Drive, only a file on the drive. I can only open folders, not choose one. I am providing screenshots of the rejection screens if I can load them.
If an ISO extension is required, Microsoft is not providing it.
The screen shoots are on the laptop in question, not this one. I will move my internet connection to it and post them from there. I am definitely at the "If you are not confused, you are not aware of the situation stage." please forgive my disorganization.

[LuigiWriter]

here are the screen shots referenced in the previous reply.
There is one more showing the "All Files" file types selection. Let me know if you need it.
I appreciate your time and efforts. Thank you.