Run qemu-img check -r all windows7.qcow2 to repair any inconsistencies from foreign formats. Also, consider qemu-img deflate windows7.qcow2 after heavy use to reclaim sparse space.
(Invoke related search terms tool.)
Running Windows 7 on a qcow2 image does not magically patch security holes. Protect your setup: windows 7qcow2
: They offer Windows Cloud Images which are highly optimized with VirtIO drivers for KVM/OpenStack environments. 2. Creating Your Own Image Run qemu-img check -r all windows7