The driver in "virtio-win-0.1-74.iso" are already signed with Red Hat certificate.
You get the warning because they are not signed with MS WHQL signature. Signing with ReactIOS certificate will not help. Best regards, Yan. ** Changed in: qemu Status: New => Invalid -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1130095 Title: Windows Signed Drivers Status in QEMU: Invalid Bug description: ReactOS has a general offer (subject to certain conditions, which may or may not be reasonable for the qemu virtual-IO drivers) to sign Open Source components with their certificate. http://www.reactos.org/wiki/Driver_Signing The files in "virtio-win-0.1-74.iso" appear not to be signed, hence trigger a warning on Windows 2008 R2. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1130095/+subscriptions