If you have a Windows 7 Lite ISO (from a trusted source), you can create the perfect qcow2 tailor-made for your hypervisor.
A "Lite" version typically means:
: An official "lightweight" version released by Microsoft for low-end hardware. It is more stable and secure than community mods but slightly heavier than Tiny7. Windows 7 Embedded Standard windows 7 lite qcow2 best
: This is widely considered the "holy grail" for low-resource environments. It can be reduced to a tiny 321 MB ISO , and once installed, it takes up less than If you have a Windows 7 Lite ISO
Boot the VM, mount the VirtIO ISO manually inside Windows (drive D:), go to Device Manager, right-click "Ethernet Controller" → Update driver → Browse for driver on the VirtIO ISO's NetKVM\w7\amd64 folder. and once installed