This isn’t the forum for PR device owners. We don’t own those devices, so don’t have experience.
Users of the linked PR forum do own PR devices, and may be able to help with specific issues with your PR device.
If you have the device mapped as a network drive in Windows file explorer, you should be able to move files from one drive to another, just like any other named drive.
Are you using Windows file explorer to access the drive? If not, then how are you accessing it?
ps. You might want to speak to the owner and administrator of the device you are using.