Windows 7qcow2 Direct

# Create a 40GB QCOW2 image
qemu-img create -f qcow2 windows7.qcow2 40G
QCOW2 can be slow if not tuned. Apply these settings inside Windows 7.
There are reputable open-source projects that provide these images specifically for developer testing.
Windows 7 tends to fragment QCOW2 images over time. Reclaim space: windows 7qcow2
Inside Windows 7: Run defrag C: then sdelete -z (to zero empty sectors).

On the host:
qemu-img convert -O qcow2 -c windows7.qcow2 windows7-compressed.qcow2

The -c flag enables compression, often reducing a 40GB thin image to 12-15GB. # Create a 40GB QCOW2 image qemu-img create
Typical QEMU command to start installation:
qemu-system-x86_64 \
  -enable-kvm \
  -smp 2 \
  -m 4096 \
  -drive file=win7.qcow2,format=qcow2 \
  -cdrom windows_7_install.iso \
  -boot d

Important drivers: Windows 7 does not include native VirtIO drivers. You will need: The -c flag enables compression, often reducing a

Recommended: Use a pre-made VirtIO driver ISO from Fedora’s repository.
This is the copy-on-write power: 20 Windows 7 VMs might only consume 15GB of host storage.

sudo dd if=/dev/sda of=windows7.raw bs=4M status=progress
qemu-img convert -f raw windows7.raw -O qcow2 windows7.qcow2

Warning: Windows 7 may complain about HAL (Hardware Abstraction Layer) changes. Boot from the Windows 7 ISO, run startup repair.
qemu-img info win7.qcow2