Open external hard drive on laptop how (Windows)?
Plug in, search for the new data carrier / drive in Explorer and open it, done.
Connect - hard drive is recognized - use.
USB is a "plug and play" system. I.e. You only have to plug in the USB device, then you can use the device.
So if your hard drive is not defective, you can open it with Windows Explorer.
Once it has been initialized and formatted, it must be recognized automatically when it is plugged in.
Desktop> This PC> Devices and Drives
All the devices that are connected internally and externally are in there.