To get around this you must temporarily disable the signature verification process.
Solution
Disable signature verification of drivers:- Go to Start Menu > Run and type the following command:     
- bcdedit /set nointegritychecks ON
 
- Restart the PC and install the unsigned driver
- To enable back the signature verification, type the following command:- bcdedit /set nointegritychecks OFF
 
- Restart your PC
