Hard Disk Drives somehow blocked

[Callum]

We have just moved from Windows 7 to Windows 10, and staff are suddenly facing an issue whereby USB-powered 'Hard Disk Drives' do not show up in This PC, but small/typical USB sticks show up fine. In other words, small USB sticks work fine, but the big block USB drives do not appear. Administrators can see them all fine, but network users cannot. What policy could be blocking this?

 

From Group Policy, we only hide/disable the C drive.

[chazzy2501]

external hard disks drives usually install a few new drivers like scsi adapters etc. maybe a class type is being blocked? You've blocked driver installation?