Multiple GPU Windows System

[ptrem]

Hi,
I have a Workstation with two RTX A6000 GPUs and a Windows System 🙈
and I would like to use both GPUs with Lightning-AI.
It's possible to use just use one of the GPUs but i get the following error if I try to use both GPUs.

The training works fine for:

trainer = pl.Trainer(
        accelerator="gpu",
        devices=1,
        max_epochs=epochs,
        logger=wandb_logger)

But I can't use for example devces=2, devices=[0, 1] or devices=-1.
In every case I get the following error:
RuntimeError: Distributed package doesn't have NCCL built in

Has anyone an idea how to run Lightning on Multiple GPUs on a Windows System?
Thanks