[CentOS-virt] can't mount a bootable flash drive

Hi All,

Scientific Linux 7.2

# rpm -qa *kvm* qemu-kvm-1.5.3-105.el7_2.3.x86_64 pcp-pmda-kvm-3.10.6-2.el7.x86_64 qemu-kvm-common-1.5.3-105.el7_2.3.x86_64 libvirt-daemon-kvm-1.2.17-13.el7_2.3.x86_64

I can mount NTFS flash drives on my Windows virtual machines by Add Hardware -> USB Host Device. They work fine.

Except for one bootable Windows 7 Pro OEM x 64 USB flash drive I use for installing Windows 7. In Windows, under devices I get a bang mark saying the device failed to start.

This same flash drive, when set as the bootable drive does boot into the Windows 7 install dialog.

What am I doing wrong?

Many thanks, -T