But virt-manager is just a convenience, under the hood it's just running qemu.
And I'm pretty sure there's a way to do windows on xen as the big tech companies offer virtualized windows.
Yes, you may need to install an "agent" into the guest to e.g. gather detailed performance statistics from within the VM.
Indeed, under the hood it runs Qemu, but there is also a pretty thick cruft of libvirt on top of it, to store the VM configuration and collect logs, and also manage the networking and storage.
I'm not sure about Wi***ws on Xen, because there was a Mi*****ft's own virtualization technology, competing with Xen. So they might just refuse to make a version of the kernel capable of running on top of Xen hypervisor.
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