There's a bug in virt-install and virt-manager on Ubuntu 8.10 that does not let you run Windows XP as a guest under KVM. During the Windows installation, the guest needs to be rebooted, and then you get the following error, and Windows XP refuses to boot: "A disk read error occured. Press Ctrl+Alt+Del to restart". This guide shows how you can solve the problem and install Windows XP as a KVM guest on Ubuntu 8.10.
via techfuga.com