What's the actual error?
Yes virt-v2v can install drivers. You need the virtio-win package
from RHEL 7, since the WHQL'd drivers are not freely redistributable
(or at least, the situation is complicated).
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine. Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/