It's almost impossible to work with hikey at the bootloader stage on a windows machine due to the lack of compatible drivers. At least from personal experience, if you're lucky enough to have it working on your windows machine, then the regular google usb driver from Android Studio should just work, which I assume is already installed on your machine, since you have adb working. If it doesn't work, then you might have to spend a lot of time and effort to try to find, install and test different drivers online to try to get it to work, and possibly still fail in the end. Sometimes installing new drivers end up breaking connections to existing devices as well. A linux machine is highly recommended.