Why does my Iomega HDD 320GB external hard drive not work on my windows 10?

[Windows Central Question]

The portable hard drive works on my XP, Vista, 7, and 8. When I try to access it all I get is working on it. It did open once but wouldn't open all my files. There is still over 290 GB of space avalible.

 

[Tony Clegg]

Could be lots of things. What format is the drive in (FAT32, NTFS, other etc). If you are able to connect to an OS on an older OS, it may well be worth backing them up on that, then format on the Win10 PC then look at copying the files back. Sounds drastic, but that's something I would consider.