While we the topic of VirtIO drivers has already been touched in Sarab’s post on Installing Windows VM and VirtIO drivers, we would like to bring two more KBs to your attention.
N.B! Nutanix does not release or maintain VirtIO drivers for Microsoft Windows Server 2008. However, you can still use stable VirtIO drivers available from Fedora project website.
Nutanix recommends to use the Stable VirtIO-Win drivers.