Unidentified network issue with virtio NIC cards in Windows 2008 R2 VM on RHEV

Issue

• All the windows 2008 R2 VM has an issue with the VirtIO Network card driver.
• Whenever we restart the vm the network card had a yellow sign after the server reboot.
  Which meant that windows did not identify the network interface or there was no driver for it.
• So we go to the network manager in windows and disable and enable network card, then it works again.