I went thru that thread but have issues.
Did the diskpart, clear etc.. Set the device to uaehf.device and in WinUAE I have it set to "UAE" for the hard drive. When I go to hdtoolbox I see the interface as scsi, but my only valid option is Change Drive Type and thats it. I cannot partition it in HDToolbox. The Drive status is "UNKNOWN"
Try using a different device. Try scsi.device. I think there is another device name you can try too but I can't remember.
Have you selected the 'get information from drive' or similar button? (HDToolbox)
In the WinUAE settings, I believe one of the config setting switches enables you to enable removable drives (to show up on the Amiga side) - Is this selected?