If no signed driver exists, and you are aware of the risks in using unsigned drivers, (accepting responsibility for any problems it causes,) there is a Policy setting available to turn off the requirement.
Click start, and type gpedit.msc
ENABLE the option for code signed drivers at:
User Config/Admin Templ./System/Driver installation
then set the drop box to "Ignore"
Rating posts helps other usersMark L. Ferguson MS-MVP