Problem with VirtIO in Windows Server 2012 r2 installation

Hello, I am having difficulties installing the VirtIO drivers when I try to install Windows Server 2012 r2, I always get the message "no signed device drivers were found. Make sure that the installation media contains the correct drivers, and the click OK ". I followed the steps of both the official proxmox guide and in several forum posts, I tried everything and I still can t get it to work.…