: Standard Windows 7 installations lack Virtio drivers. You must manually install these during or after setup for high-speed disk and network I/O.
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The QCOW2 format is the native disk image format for QEMU and KVM (Kernel-based Virtual Machine). Unlike "raw" images, which occupy the full disk space immediately, QCOW2 files are thin-provisioned. This means a 100GB Windows 7 virtual disk might only take up 15GB on the physical host—growing only as data is written. Furthermore, it supports snapshots, allowing users to "save" the state of Windows 7 before making risky changes, a feature indispensable for testing legacy drivers or older software suites. Why Virtualize Windows 7 Today? windows 7qcow2
