Welcome to the community, Nick!
You can try using your HDD manufacturer's diagnostic tool and see if it incorporates the feature of WRITING ZEROS. If not, look for a formatting tool on their website. The WRITING ZEROS low-level format will do a full erase on your drive to the point of no return/recovery, so make sure you have a backup of your essential files.
If you're trying to boot from the USB into Windows in order to erase the drive, make sure you have the USB first in the boot priority in BIOS.
Another possible solution would be to use a DOS version of such HDD formatting or a diagnostic tool which would let you do the same without booting into any OS. This is our Data LifeGuard Diagnostic tool (in DOS version), in case you cannot find your brand-specific utility (make sure you read through the features of the software and follow the instructions):
http://products.wdc.com/support/kb.ashx?id=LbGbyI
Good luck! Hope it helps!
SuperSoph_WD