In Win 10 I have a Seagate External HD 2tb. The only thing it cannot do is write to the drive. The drive in the Win 10 PC is listed and so are the files. I can open the files but cannot back them up to this HD. I tried backing up my quicken files and documents in Word but was not able to write them to this HD. I can write the files to another external HD (Flex Agent) but not to the External Desk HD. The S/N is NA4LBNBM. Seagate cannot find the firmware for this S/N. It is list in the Seagate tools app. A return e-mail to >forums@tomshardware.com< was bounced back and undeliverable.