gabmus

I literally helped my brother boot into a vm from an actual windows install drive with virt manager, without even copying the disk into an image, just a couple of weeks ago. Some features might not work like 3d acceleration and such but the vm boots, you can login, access the desktop and go about whatever you need to do. AFAIK a VM emulates standard compliant hardware that windows should always be able to boot into, otherwise even just the installation iso would fail to boot.

If you have enough space and plan on using libvirt or any other virtualization technology that just lets you use img files as virtual disks, you can just dump the entire disk with dd:

(replace /dev/sda with the disk containing windows)

dd if=/dev/sda of=./windows-disk.img status=progress