[Users] Problem with Win 7 VM creation

Hello everybody and Antoni, I have changed my NFS server to my engine machine and finally I have had to create a Fedora 17 VM machine in my oVirt system and now I'm trying to create a Win 7 VM machine and when I want to Run once my machine, in Boot options I don't have the "virtio-win" driver to attach to floppy VM and when machine try to install system in virtual hard disk it ask for a driver for the disk. How can I install this driver and to be attached to my VM floppy? Many thanks in avanced, Juanjo.