Modern motherboards require USB drivers (also nvme drivers, if installing on nvme drive) integrated into windows 7 installation.
You can use Gigabyte windows USB installation tool, to integrate the drivers.
https://www.gigabyte.com/Support/Utility?kw=windows&p=1
Or install windows 10 instead.
May be start by listing your system specs then (at least motherboard model name).Actually my system is pretty old and doesnot have usb 3.0.
I've never had any problem installing Windows 7 from a USB 2.0 port.It doesn’t matter Windows 7 won’t and start without USB drivers