The Digital Archaeologist’s Guide: Installing Windows 8.1 in a QCOW2 Environment

Subject: Windows 8.1 QCOW2 Install Focus: Virtualization, QEMU/KVM, Storage Optimization, and Legacy OS Preservation

While the tech world races toward Windows 11 and beyond, there remains a distinct need for Windows 8.1 in specialized environments—be it for legacy software compatibility, industrial control systems, or retro-gaming preservation. However, running this operating system using modern virtualization technologies presents a unique set of challenges and opportunities.

This article explores the deep technical process of installing Windows 8.1 into a QCOW2 (QEMU Copy On Write version 2) disk image. We will move beyond basic "next-next-finish" instructions to examine the architecture of QCOW2, the nuances of UEFI emulation, and the specific optimizations required to make this notoriously tile-heavy OS perform like a native machine.

Create a Snapshot

virsh snapshot-create-as win81 clean-state "Fresh install with drivers"

Closing notes

This workflow gets Windows 8.1 running in a qcow2 image with solid performance using virtio drivers. Use virt-manager or libvirt for easier management; use qemu-system directly for fine control. If you want, I can produce:

• A tailored libvirt XML for your CPU/RAM/disk specs, or
• A step-by-step walkthrough with screenshots, or
• A script that automates qcow2 creation + virt-install for specific resources.

Which of those would you like?

Here’s a solid, structured review of installing Windows 8.1 as a QEMU QCOW2 virtual machine. It covers performance, setup steps, driver considerations, and overall suitability.

Recommended device choices

• Disk bus: virtio-scsi for best compatibility and features (hotplug).
• Network: virtio-net for best throughput.
• Video: qxl (with spice) for good graphical experience; or virtio-gpu if supported.
• Sound: AC97 or Intel HDA (use corresponding drivers in Windows).
• Input: USB tablet for pointer integration.

Step 2: Create VM with Custom Settings

Proxmox GUI:

1. Create VM → OS: Windows 8/2012 (Select type: Windows 8/2012)
2. Hard Disk: Bus/Device = VirtIO Block. Size = whatever you created. Important: Do not add the disk yet if you want to install via ISO – or add it, but also add an extra SATA disk? Better: Add the disk as VirtIO, but first boot from Windows ISO and VirtIO ISO.
3. CD/DVD Drive 1: Windows 8.1 ISO
4. CD/DVD Drive 2: VirtIO driver ISO (use virtio-win.iso)
5. Display: SPICE or QXL (for better GPU)

The key: When starting the VM, press a key to boot from DVD. At disk selection, no disk appears. Click Load Driver, browse to the VirtIO CDROM → viostor\w8.1\amd64. The VirtIO disk appears. Install.

Benchmark:

A well-tuned Windows 8.1 on QCOW2 (with VirtIO) should achieve near‑bare‑metal disk speeds – over 1 GB/s sequential with NVMe backend and cache=none.

Create VM with virt-install (example)

UEFI example with virtio disk and virtio NIC:

virt-install \
--name win8.1 \
--ram 8192 \
--vcpus 2 \
--cpu host \
--os-variant win8.1 \
--disk path=/var/lib/libvirt/images/win8.1.qcow2,format=qcow2,bus=virtio,size=60 \
--cdrom /path/to/Win8.1.iso \
--disk path=/path/to/virtio-win.iso,device=cdrom \
--graphics spice \
--video qxl \
--network network=default,model=virtio \
--boot uefi

Notes:

• Use --boot uefi only if OVMF installed.
• If using BIOS, omit --boot uefi.
• For better graphics, use SPICE + QXL/Virtio GPU or passthrough GPU if available.

Step 3: Create a Virtual Machine

You can create a virtual machine (VM) and install Windows 8.1 on it using the following command. Before running the command, replace /path/to/win8.1.iso with the actual path to your Windows 8.1 ISO file.

sudo qemu-system-x86_64 \
  -enable-kvm \
  -m 4096 \
  -vga virtio \
  -display sdl,gl=on \
  -device virtio-tablet \
  -device virtio-keyboard \
  -smp 2 \
  -cdrom /path/to/win8.1.iso \
  -boot order=d \
  -device virtio-disk0 \
  -drive file=win81.qcow2,format=qcow2,if=virtio \
  -netdev user,id=network0 \
  -device e1000e,netdev=network0 \
  -soundhw hda \
  -device intel-hda -device hda-duplex

However, for actually creating a .qcow2 image and then installing Windows into it, you'll first need to create the image:

qemu-img create -f qcow2 win81.qcow2 60G

Then, use a slightly modified command to boot from the ISO and install Windows onto the .qcow2 image:

sudo qemu-system-x86_64 \
  -enable-kvm \
  -m 4096 \
  -smp 2 \
  -cdrom /path/to/win8.1.iso \
  -boot order=d \
  -drive file=win81.qcow2,format=qcow2,if=virtio \
  -netdev user,id=network0 \
  -device e1000e,netdev=network0

Step B: The VirtIO "Chicken and Egg" Problem

When booting the Windows 8.1 installer, you will encounter a screen asking "Where do you want to install Windows?" The list will be empty.

This is because the virtual hard drive is on a VirtIO controller, which the installer views as an alien device.

1. Load the VirtIO ISO into a second virtual CD-ROM drive.
2. Click "Load Driver" in the installer.
3. Browse to the Win8.1 folder on the VirtIO ISO -> amd64.
4. Select the Red Hat VirtIO SCSI controller.
5. The QCOW2 disk will suddenly appear.