No Boot after installing RDS on Windows Server 2025

[aroelle]

Hello, I have a very strange problem with Windows Server 2025 and RemoteDesktop-Services.

What happened:
Installed a Domain-Controller with Windows Server 2025 on Proxmox 8.3.0 - used virtio 0.1.266 and everything works fine.
Installed a 2nd Windows Server 2025 and joined Domain.
Then I installed Remote-Desktop-Services.
The installation initiates an automatic reboot - and the reboot fails - starting automatic repair.

There are no disks visible when using diskpart in command prompt in recovery environment.
That explains, why Windows is unable to boot.
But why does this happen?

- I just re-installed the server again - same error.
- I re-installed the server using virtio 0.1.262 - same error ( I know that there are problems with this version)
- I re-installed the server using virtio 0.1.248 - same error
- I installed the driver manually in Windows recovery environment (pnputil -i -a vioscsi.inf)
-----> Drives are now visible with diskpart, but still no boot.
- I wanted to re-install the server, but all drives are offline in Windows-Setup.
-----> Found thread in this forum to enable all drives in Proxmox boot options - but still no boot
- I installed the driver via command prompt, started diskpart and used "clean" to empty the drives

I finally gave up and installed Windows Server 2022, joined domain and installed RDS - everything works fine.

I cannot figure out, what is causing this problem.
Is this a Windows Server 2025-with-RDS-issue?
Or is it a Windows Server 2025-with-Proxmox-issue?

Has anyone experienced similar problems?

 

[_gabriel]

to dig out, try another VM with vDisks as sata or ide.

 

[aroelle]

I installed a second DC with IDE only.
Everything was fine in the beginning.
I added Active-Directory-Services, promoted to DC, restart, Boom!
Back to automatic repair.
I can boot the VM in Protected-Mode but it won't boot normally anymore.

The other VM I installed yesterday did not start either, when I restarted the Host today.
Yesterday everything worked fine - several reboots - no problem.
I shut down VMs and Host as it should be.
Today I started Proxmox, started the VM - automatic repair.

This is ridiculous.
I found several posts in this forum like this one:
https://forum.proxmox.com/threads/windows-server-2025-und-nested-hyper-v.157565/page-2

He wanted to install the Hyper-V-role and ran into the same problem.
I installed Remote-Desktop-Services on VM1 (SCSI) and Active-Directory on VM2 (IDE) and the problem occured.
The other VM #3 had no roles installed - it supposed to be an Application-Server.
Next day - same problem as well.

I re-installed all VMs with Server 2022 and no problems so far.
It has to be some problem with Server 2025 and Proxmox, as far as I can tell.

 

[_gabriel]

what is your CPU host ?
what is VM's CPU type ?

edit: No problem here, with Windows Server 2025 as RDS ( without AD ) as VM on fresh PVE on new HPe DL20 Gen11 (Xeon E-2436).

 

[aroelle]

Thx for your reply.

My server is a new Lenovo ST650 V3 with an Intel Xeon Silver 4510 (12 Cores / 24 vCPUs).
I always use "Host" as CPU type in my VMs.

Everything installed from scratch two days before.

 

[_gabriel]

I can boot the VM in Protected-Mode

do you mean Safemode ?