Windows 7 Qcow2 File -

qemu-system-x86_64 \
  -machine pc-q35-2.9 \
  -cpu host \
  -smp 2 \
  -m 4096 \
  -drive file=win7.qcow2,format=qcow2,if=ide \
  -cdrom Windows7.iso \
  -cdrom virtio-win.iso \
  -boot d \
  -vga qxl \
  -usb \
  -device usb-tablet

Note: During install, when no disk is found, load the VirtIO SCSI driver from the attached ISO.

qemu-img convert -f raw win7.raw -O qcow2 win7.qcow2

qemu-img create -f qcow2 win7.qcow2 40G

To VirtualBox (VDI):

qemu-img convert -f qcow2 -O vdi win7.qcow2 win7.vdi

To VMware (VMDK):

qemu-img convert -f qcow2 -O vmdk win7.qcow2 win7.vmdk

qemu-img convert -f vdi -O qcow2 windows7.vdi windows7.qcow2 windows 7 qcow2 file

To apply changes from a snapshot back to the original: qemu-system-x86_64 \ -machine pc-q35-2

qemu-img commit windows7_snapshot1.qcow2