Windows 7 is no longer supported by Microsoft, but it remains a popular choice for developers, researchers, and retro-tech enthusiasts who need to run legacy software in a virtual environment. Using a .qcow2 file is the most efficient way to get Windows 7 running on Linux-based virtualization tools like QEMU or KVM. What is a .qcow2 File?

Need a .vmdk or .vdi instead? Use qemu-img convert :

Cannot activate Windows

Snapshots

: You can easily save the state of your Windows 7 VM before making risky changes.

Saves Space

: It only uses actual disk space as data is written, rather than pre-allocating the full size.

This means your VM is trying to use an IDE driver, but the image was built for SCSI/VirtIO. Solution: edit the .qcow2 metadata or attach a secondary VirtIO driver disk during boot.