1
You should not need a separate driver for that portable drive, it would use the default WIndows drivers, and I checked the HP website, they do not provide any specific drivers for that drive.
What problems are you experiencing with that drive, if it is not working in your PC, did you try connecting it to another PC to test if it is working there.
2
Connect that drive to your PC.
Right click your Start Button and open Disk Management.
Expand the bottom pane in Disk Management so all drives are visible in that pane.
Please provide a screenshot of that Disk Management window.