HyperV cannot unmount installation media.

Hello, I've recently installed a Win11 VM under HyperV.
After deleting the installation ISO file from the host machine, the VM does cannot start as it cannot find the ISO - this is to be expected.
However, if I try to unmount the ISO or remove the whole virtual dvd drive and start the VM, I get the same error and the DVD drive along with the mounted iso comes back.
I just cannot unmount or remove it.

Can you set media to none?

Your mistake was deleting the ISO file from the host machine before disconnecting it from the VM. You might try to put it back on the host. After that you could try selecting "None" before you start the VM. After verify that it boots OK you can delete the ISO on the host machine.

I forgot I still had my ISO for Windows 11 24H2 still mounted. I just went into the settings and selected "None" for media. It then booted fine.

MisterEd said:

Your mistake was deleting the ISO file from the host machine before disconnecting it from the VM. You might try to put it back on the host. After that you could try selecting "None" before you start the VM. After verify that it boots OK you can delete the ISO on the host machine.

I forgot I still had my ISO for Windows 11 24H2 still mounted. I just went into the settings and selected "None" for media. It then booted fine.

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I do not try think you even need to put it back on host.

You can move DVD drive to the bottom of the list so that your VM should not look for a bootable DVD media. ISO file.

Bootmgfw.efi must be on top as seen in my screenshot.

suatcini54 said:

You can move DVD drive to the bottom of the list so that your VM should not look for a bootable DVD media. ISO file.

Bootmgfw.efi must be on top as seen in my screenshot.

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I usually put the .vhdx file to the top as your advice only applies for gen 2 uefi installations. Having said that win 11 vms are gen 2 (although gen 1 legacy bios W11 installations are possible but require a bit of effort).

@cereberus Thank you for your contribution to my post. Much appreciated. As is well known, there are strict requirements for Windows 11 installations. Since Hyper-V Gen 2 VMs easily meet those strict requirements, I didn't think anyone would attempt to circumvent them except in scenarios where the users of PCs with incompatible hardware wished to check if bypass tricks of the requirements would work when it was time to install Windows 11 on actual incompatible hardware. I do it sometimes for my partly-compatible PC.

It doesn't matter if the optical drive is at the top or the bottom. The VM is referencing an ISO that no longer exists. The drive just needs to be set to none, as mentioned in post 2.

One of the bugbears of using HYPER-V for VM's on domestic rather than corporate machines (and Hyper-V was originally ported from Servers so more of a business thing) is that it doesn't have USB re-direct i.e no dynamic attaching / removing usb devices - so any USB devices have to be defined to the Virtual machine at VM power on. Also for Non USB devices I think it doesn't have any facilities to add those either or non Disk type USB devices.

So if you want to remove the install iso / DVD type device then you have to remove it from the virtual machines settings.



Within its limitations HYPER-V is actually quite good -- one problem though is on an increasing number of Linux distros - X11 / XORG is being phased out and replaced by Wayland which doesn't play very nice with Ms's standard RDP protocol so getting sound to work natively on a Linux VM under HYPER-V is a bit questionable. Debian is one of the few that still use X11/XORG on its LTS version so that one is OK but for others -- it's still "awaiting development".

However if you just want to use a Linux VM as a file, backup and multi-media server its fine !!. If you need sound then I'd suggest either dual booting or use something like oracle's VBOX which seems these days to work a lot better than the mess that VMWare workstation is becoming since Vmware was taken over. At least Oracle is consistent and reliable.

If you use physical vhdx files then dual booting is not a problem - as well as Windows versions you can also boot a Linux distro from the standard "Blue" windows boot screen. E,G




(In addition to these other Windows installations) !!



I'm running these and the following Windows systems all from an external 2TB SSD type nvme device in a nvme->usb3 / usbc adapter. wiorks perfectly.



Cheers
jimbo