The ask here is to add a RegFlushKey call to the Windows installer to make sure that driver-related registry keys are persisted. These keys may be lost if the VM crashes soon enough after installation. Please see the original bug 1455122 for details. Thanks!
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory, and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHEA-2018:1517