proxmox windows guest no drive install

3 min read 24-02-2025

Installing a Windows guest virtual machine (VM) on Proxmox VE without using a physical drive or pre-created disk image might seem counterintuitive. Traditionally, you'd create a virtual disk (VMDK, VHD, etc.) beforehand. However, there are scenarios where you might want to install Windows directly, attaching the disk later. This article details how to accomplish a Proxmox Windows guest installation without a pre-created drive, focusing on the steps and considerations involved. This technique is particularly useful for situations where you need to precisely control partitioning, or when using specific disk imaging tools after the initial installation.

Preparing for Installation: The Proxmox Side

Before we begin, ensure you have:

A running Proxmox VE server: This is fundamental. Update your Proxmox installation to the latest stable version for optimal performance and compatibility.
Sufficient Resources: Allocate enough CPU cores, RAM, and network bandwidth for your Windows guest. Windows 10/11 requires significant resources; plan accordingly.
An ISO Image: Download the official Windows ISO file from Microsoft. You'll need this for the installation process.

1. Creating the VM

Navigate to the VM creation screen: In Proxmox, go to "QEMU/KVM" and click "Create VM".
Basic Configuration: Choose a suitable name and select a suitable version of Windows as the operating system. This selection isn't critical since we aren't using a pre-existing disk, but it helps Proxmox with default settings (though you'll likely need to adjust these later).
Memory and CPU: Assign adequate RAM and CPU cores. Refer to Microsoft's system requirements for your chosen Windows version.
Network: Configure your virtual network interface (e.g., bridge or NAT). Choose the one appropriate for your network setup.
Storage: Crucially, leave the "Storage" section blank. We're not using a pre-created disk image at this stage. Click "Next".

2. Boot from ISO

Add the ISO: On the next screen, in the "CD/DVD Drive" section, click "Browse" and select the Windows ISO file you downloaded.
Review and Create: Review your settings. If everything looks correct, click "Finish".

Installing Windows: The Guest Side

Now, the VM will boot from your Windows ISO. Follow the standard Windows installation steps:

Language and Region: Select your preferred language and region.
Product Key: Enter your Windows product key if you have one (this can also be skipped initially, though activation will be required later).
License Agreement: Accept the license terms.
Custom Installation: Choose the "Custom: Install Windows only (advanced)" option. This is essential for the "no drive" approach.
Drive Selection: Here’s where the absence of a pre-created disk comes into play. You will see an unallocated space. DO NOT PROCEED WITH THE DEFAULT INSTALLATION AT THIS POINT.

Post-Installation Disk Management

This is the critical step differentiating this method from a standard Windows installation within a VM. At this stage, several options exist:

Create a Virtual Disk Later: After completing Windows installation, shut down the VM in Proxmox. Then, create a new virtual disk using Proxmox's storage settings. Attach this newly created disk to your VM's configuration. You can use your preferred partitioning tool (Disk Management within Windows or a third-party tool) to assign drives. This gives you maximum control and allows for more advanced configurations, such as multiple partitions.
Using a Disk Imaging Tool: Alternatively, consider using a disk imaging tool like Clonezilla or a similar program. Install Windows, then use this tool to capture the image after the initial setup, allowing for rapid cloning and deployment of identical VMs. This is a great option for building multiple identical Windows instances.

Important Considerations

Driver Installation: You may need to install specific drivers for your virtual hardware after installation depending on your Windows version and virtual hardware setup. These drivers are usually provided by Proxmox or your virtualization hypervisor.
Guest Additions: Install Proxmox Guest Agents for improved integration and performance.
Snapshots: Creating snapshots after the Windows installation is complete is highly recommended for easy rollback and backups.

This method of installing a Windows VM on Proxmox without a pre-created drive offers flexibility and control. Whether you choose to create a disk afterwards or use disk imaging, remember to carefully manage your partitions and ensure sufficient space for your needs. Always back up your important data.