How to create a Windows Server 2025 VM under Proxmox

Vorbereitende Schritte:

In our guide, we will create a VM with Windows Server 2025. To do this, we first need the Windows image. You can find this ISO file directly on the corresponding download page from Microsoft.

Furthermore, Windows requires a special driver to recognize virtual hard disks. You can find this VirtIO driver for Windows in the Proxmox Wiki.

You must upload these two ISO images (Windows and driver) to the local (pve) partition and then to the ISO Images folder.

Step-by-step instructions

1. Click Create VM in the upper right corner of the Proxmox GUI.

2. Under General, give your VM a name.

3. Under the OS tab, select the ISO for the VM you want to create. For the Windows Server 2025 VM, also check the “Add additional drive for VirtIO drivers” box and point it to the VirtIO ISO file below.

4. In the next step, specify the underlying BIOS under the System tab. In the case of Windows: UEFI, which is why you must select EFI Storage.

5. Next, configure your boot drive under the Disks tab. Windows requires at least 70 GB. However, you can add additional hard drives if necessary.

6. For CPU and memory, select the number of usable CPU cores and RAM memory to be allocated.

Experience has shown that four cores, eight GB RAM, and 70 GB disk space are a practical configuration for medium workloads. However, this can vary depending on requirements. Note: Any change to the hardware settings requires a reboot of the VM.

Microsoft's minimum requirements for Windows Server 2025

7. Final step: Under Network, specify a network bridge as the network interface.

8. Lastly, you can review and confirm all the settings you have made.

Start VM

To start the VM you just created, you need to go to the VM's context menu. Here, under Console, you can see the VM's screen and control its startup and shutdown.

After the VM starts, the Windows 2025 installation begins. If the system cannot find a hard disk, you must select the appropriate drivers from the VirtIO CD under Load Driver. (Here: w2k25)

You can then proceed with the Windows 2025 installation as usual.