I had a late 2009 IMAC. I used this Hitachi ext drive for backup. IMAC died. Replaced with new Windows 10 pc. I would like to use this drive for backup for new pc.
PROBLEM: PC sees this drive as CD drive. PC also only sees 300mb, which is full. Disk Mgmt in Windows does not give option to format or delete partition. Drive is formatted UDF. I would like to completely erase drive and re-format to NTFS. HELP?!
First try the format and diskpart tools via command line; they often allow more than the GUIs.
If that doesn't work, you could
boot up a Linux CD/USB and use GParted (or command-line tools like fdisk/parted), e.g. GParted itself provides an .iso image dedicated to disk management tasks;
blank out the first ~8 MB of the disk using dd, making Disk Manager see the disk as uninitialized:
dd --list
[*carefully* find and write down the Harddisk number of your USB disk]
dd if=\\?\Device\Harddisk2\Partition0 of=backup.img bs=1M count=8
dd if=/dev/zero of=\\?\Device\Harddisk2\Partition0 bs=1M count=8
You can use diskpart command line tool to erase partition table. This will wipe the disk completely.
Press Win and type diskpart, press Ctrl+Shift+Enter to run it as administrator. Windows will ask you for confirmation.
Type the command list disk and press Enter, it will list all available disks along with their indices. Take note of your disk's index. Be careful not to select some other disk. Here are example results from my laptop:
DISKPART> list disk
Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 931 GB 26 GB
Enter command select disk <index> (substitute <index> with your disk's index, for example select disk 0)
Now type list partition and make sure it looks like the disk you wish to nuke. If you're sure it's the correct one, type clean and confirm with Enter.
Finally, open Disk Management (the quickest way is to right-click the Start button and select Disk Management). It should ask you to initialize the drive. Let it do that and you're good to go!
