Xen does _not_ have the ability to run Windows under Paravirtualization. The Windows kernel does not have Paravirtualization built in, a requirement to take advantage of Paravirtualization. Xen can only run Windows on CPUs with Virtualization Technology included. And VMware also supports Paravirtualization for Linux. If this customer had been persuaded to to do a comparison, this project would have used VMware, I have no doubt. Some other reseller besides Moose will probably read this and engage the customer, displacing Xen.