Oracle Virtualbox on Windows11 virtualized in ProxmoxVE

[it.area]

Good morning everyone, I installed a windows11 machine on Proxmox Ve 8.2.2.
On this machine I would like to run a Windows 2008 r2 machine virtualized via Oracle VirtualBox.
When I turn on the machine I get this error.

WHvCapabilityCodeHypervisorPresent is FALSE! Make sure you have enabled the 'Windows Hypervisor Platform' feature. (VERR_NEM_NOT_AVAILABLE).
VT-x is not available (VERR_VMX_NO_VMX).
Exit code:
E_FAIL (0X80004005)
Component:
ConsoleWrap
Interface:
IConsole {6ac83d89-6ee7-4e33-8ae6-b257b2e81be8}

Can someone help me?
Thanks a lot

 

[fireon]

On this machine I would like to run a Windows 2008 r2 machine virtualized via Oracle VirtualBox.

Why such a cascade?

https://pve.proxmox.com/wiki/Nested_Virtualization

You must also enable nested virtualization on the windows 11 machine:

Set-VMProcessor -VMName <name> -ExposeVirtualizationExtensions $true

 

[it.area]

Why such a cascade?

https://pve.proxmox.com/wiki/Nested_Virtualization

You must also enable nested virtualization on the windows 11 machine:

Set-VMProcessor -VMName <name> -ExposeVirtualizationExtensions $true

Because the direct importation desn't work the server in 2008r2 imported from Esxi 5.5 don't start

 

[SkyZoThreaD]

Because the direct importation desn't work the server in 2008r2 imported from Esxi 5.5 don't start

Try detaching the boot disk and reattach as IDE.
Or even better, attach it as virtio block, boot on server 2008 iso with virtio iso mounted on the vm as well so you can install the driver viostor wirth dism.
9 times out of 10, a non bootin windows is a disk controller issue. The other time it's UEFI instead of MBR.