Thank you for your swift response. However, still not able to connect to the ubuntu libvirtd. Have you ever seen a grown man cry? Edited /etc/libvirt/libvirt.conf as follows: listen_tcp = 1 auth_tcp = "none" Edited /etc/default//libvirt-bin as follows: libvirt-opts="-d -l" Running virsh on Vista client fails as follows: $ virsh -c qemu+tcp://192.168.1.101/system error: unable to connect to libvirtd at '192.168.1.101': errno=10061 error: failed to connect to the hypervisor Running virsh on Ubuntu server fails as follows: $ virsh -c qemu+tcp:///system Connecting to uri: qemu+tcp:///system error: unable to connect to libvirtd at 'localhost': Connection refused error: failed to connect to the hypervisor Indeed, with libvirt-opts="-d -l" in etc/default//libvirt-bin the 'default' command also fails: $ virsh -c qemu:///system Connecting to uri: qemu:///system error: unable to connect to 'var/run/libvirt/libvirt-sock': Connection refused error: failed to connect to the hypervisor The rationale for using insecure TCP was to quickly prove a concept with the minimum of fuss. Perhaps this is not the way forward. Suggestions very welcome... Tim McLeod -----Original Message----- From: Matthias Bolte [mailto:matthias.bolte@googlemail.com] Sent: 28 April 2010 15:36 To: tim.mcleod(a)simulamen.eu Cc: libvirt-users(a)redhat.com Subject: Re: Windows Client 2010/4/28 Tim McLeod <tim.mcleod(a)simulamen.eu&gt;: Nine :) You need to specify the server in this URI using a hostname or IP address: qemu+tcp://ubuntu-server.com/system You also need to change this #auth_tcp = "sasl" to auth_tcp = "none" to disable SASL authentication/encryption for TCP connections, because your libvirt on Windows is compiled without SASL support. If you need the libvirt connections to be encrypted you can switch from TCP to TLS connections using: qemu+tls://ubuntu-server.com/system For Ubuntu packaged libvirt see /etc/default/libvirt-bin and change libvirtd_opts="-d" to libvirtd_opts="-d -l" as the comment suggest and restart libvirtd using /etc/init.d/libvirt-bin restart Now you should be able to connect to the libvirtd on your Ubuntu server. Matthias