virtio-win-0.1-59.iso is a specific release of the package, provided by the Fedora Virtualization Project (and Red Hat). It contains paravirtualized I/O drivers for Windows guests running on KVM, QEMU, libvirt, and oVirt.
virt-install \ --name win10-vm \ --disk path=win10.qcow2,size=50 \ --disk path=virtio-win-0.1-59.iso,device=cdrom \ --os-variant win10 \ --cdrom /path/to/Win10_install.iso virtio-win-0.1-59.iso
: Use 0.1-59 only for legacy hosts (RHEL 7, old QEMU, Windows 7/8). For new deployments, use virtio-win-0.1.240-1.iso or newer. virtio-win-0