launch virt-manager from shell as root
set Guest VM name and Local install media
add 1 cdrom - Windows Server ISO image
set OS type: Windows and version: Windows Server 2008
set CPU and RAM amount
deselect Enable storage for this virtual machine
select Customize configuration before install
add 2 cdrom - virtio ISO image
add floppy - our floppy image
add/or create HDD image with Disk bus: VirtIO and storage format: QCOW2
set network device model: VirtIO
If everything OK - start installation process, guest vm screen accessible through Console button
