Let’s start from scratch. You’ll need a Windows 7 ISO (ensure you have a legal license key).
QCOW2 can be slow if not tuned. Apply these settings inside Windows 7.
# Convert raw to qcow2 with cluster size = 64K (better for Windows)
qemu-img convert -f raw -O qcow2 -o cluster_size=64K windows7.raw windows7.qcow2
Snapshots are perfect for Windows 7, as patch installations or registry tweaks often break legacy apps. windows 7qcow2
Create a snapshot before a risky change:
qemu-img snapshot -c pre_driver_install windows7.qcow2
List snapshots:
qemu-img snapshot -l windows7.qcow2
Restore a snapshot:
qemu-img snapshot -a pre_driver_install windows7.qcow2
Pro tip: Use virsh if you manage via libvirt: virsh snapshot-create-as windows7 clean_state --disk-only Let’s start from scratch
qemu-img convert -f vmdk -O qcow2 windows7.vmdk windows7.qcow2
You might wonder why you should use qcow2 instead of a raw disk image or VDI. There are two main benefits: