@Manuel_Jordan as we have resolved this, it seems you cannot download just the W10 .iso from within the Windows environment (OS) as it will take you to the media creation tool instead.
However, from within Linux, you are free to download either the W11 or W10, directly from Microsoft’s website and either place it on your own internal drive or directly onto the Ventoy flash drive, which will then keep it there along with your other bootable sessions of Linux.
Siince I only used the iso for a VM install within Linux, I cannot say what would happen if you booted into the Ventoy USB and selected the W10 image, it might work, but I have no experience with this.
Thanks,
Sheila Flanagan