After installation, you can compact the image:
qemu-img convert -O qcow2 -c windows_vista.qcow2 windows_vista_compacted.qcow2 The -c flag enables compression (saves space, slightly slower reads). Vista was designed for machines with 1–2 GB RAM and slow spinning disks. Modern SSDs and CPU virtualization make it fly, but there are pitfalls. Windows Vista Qcow2 Download
Introduction: Why Vista in 2025? Windows Vista—released to manufacturing in November 2006—turned 18 years old in 2024. Once maligned for its heavy hardware requirements, aggressive User Account Control (UAC), and early driver issues, Vista has since gained a niche following among retro-computing enthusiasts, software archivists, and security researchers. Running Vista inside a virtual machine (VM) bypasses its original hardware problems while preserving access to legacy software, classic games, and a piece of operating system history. After installation, you can compact the image: qemu-img