Description of problem:
In the wizard in the "parameters" stage "add windows drivers" checkbox is missing

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. choose a template that is not a windows
2. choose to customize the vm
3. try to add a "windows driver" disk

Actual results:
no checkbox to add the drivers disk is available

Expected results:
a checkbox to add the drivers disk is available

Additional info:
we may want an easy way to add the drivers disk in the "disks" tab, in case the user want to add the disk after creating the VM