You need this driver for the guest agent to report information and
generally work well in Windows. This is the communication channel for the
agent.
While this is a qemu and/or driver issues, we'll need a lot more
information to able to help you, beginning with the version of Windows, the
driver (and where it came from), etc.
Y.
OK thanks. That's why my ovirt agent is not working.
I have a Windows 2008 R2 SP1 x64. All drivers came from ovirt guest install ISO.