Use a private bridge or NAT to prevent the VM from scanning your local network.
Inside Windows 7, install qemu-ga-x86_64.msi from the virtio ISO. On the host, add:
cpupower frequency-set -g performance
qemu-img snapshot -a before_update win7.qcow2
Creating an image yourself is the most secure way to ensure it hasn't been tampered with. You will need a Windows 7 ISO file. : qemu-img create -f qcow2 windows7.qcow2 40G Use code with caution. Copied to clipboard