If VirtualBox is not showing 64-bit Operating System, Enable Hardware Virtualization or Disable Hyper-V. More suggestions are here in this post.

Inside the pop-up window, enter the Name of your VM, select its Folder (directory), and make sure the Type setting shows Microsoft Windows, with the Version option set to Windows 11 (64-bit).

There are 32-bit and 64-bit versions; Virtual PC cares about the difference. The newest version of Virtual PC supports USB peripherals and are supposed to be able to support 64-bit operating ...

VMware has a press release on their website that announces the release and availability of version 3.0 of Fusion, which brings 64-bit support along with other enhancements to the software.