It is important to note that .

Provide a generous disk allocation for your Windows 7 virtual machine (VM). A minimum of 20 GB is recommended, but 50 GB or more is ideal, depending on your usage.

You may be looking for a (to avoid manual install). The "best" in terms of convenience comes from:

Below is an outline for a technical paper focused on optimizing Windows 7 in a QEMU/KVM environment using the .qcow2 format.

virt-install --name win7 --ram 4096 --vcpus 2 --disk path=win7.qcow2,bus=virtio --disk path=/path/to/virtio-win.iso,device=cdrom --cdrom /path/to/Windows7.iso --os-variant win7 --network network=default,model=virtio --graphics spice

Configure QEMU to use the optimal disk I/O settings:

The default cluster size is often 64KB. For better performance on modern hosts, increase it to when creating the image. This reduces metadata lookups and fragmentation. qemu-img create -f qcow2 -o cluster_size=2M windows7.qcow2 60G 2. Disk Bus and Cache