First, the disk is marked as “unknown” and “Not initialized” on the left, which a brand new disk introduced to the system would be flagged as. Second, the drive size matches the size of the drive we just installed (around 1 TB), and the drive is flagged as “unallocated”, which means none of the hard drive space has been formatted or assigned a partition. Right click on the name portion of the disk entry, where it says “Disk [#]”, and select “Initialize Disk” from the right-click context menu. RELATED: In the first step of the initilization process, you’ll be prompted to choose whether you want to use a Master Boot Record (MBR) or a GUID Partition Table (GPT) for the partition style of your disk. If you want to do some in depth reading before making a choice, you can.
• Click Next. • Choose the volume size or leave the default size if you're planning to use the entire hard drive to store files. • Click Next. • Select a drive letter from the drop-down menu. • Click Next. • Select a file system from the drop-down menu.
The LaCie didn't show up in Disk Utility or System Profiler yesterday. Today, I powered on the iMac and after reading your suggestion brought up DU and again it wasn't showing - at first. On rare occasions, a Mac preference file relating to audio devices may become corrupted. This can cause a device to not show up as an input/output device in System Preferences > Sound even when there is nothing wrong with the device itself, or cause the device's MIDI ports to not show up. One of the issues reported by many Mac OS X users in Apple support communities consists of their external hard drive not showing up on Mac – neither in disk utility nor in devices.
Your new drive is not dead. You'll just need to follow Step 2 and initialize the drive. 
Nevertheless, if Windows Install also can't find the hard disk after cleaning, try wiping the hard disk. Wipe Hard Disk with MiniTool Partition Wizard If you have tried methods above, most probably MiniTool Partition Wizard has been installed or Partition Wizard Boot Disk has been created. If not, download or buy Partition Wizard now.
How To Configure New Hard That Isn't Showing Up For Mac
Then I connected in windows laptop and it got detected in USB 2.0 port but was not showing up in windows explorer. I checked in disk management and tried to open it but was not opening. Right clicking was giving me only two options: delete volume and help. All other options were greyed out. Can anyone please help here? I don't want to format the hdd.
I would check the latest drivers for some compatibility issues with XP. - more about diskpart command.
Being a 1 Mac household and an IT professional who has only supported PCs, I had a challenging time trying to figure out how to reload OSX after my husband's Mac hard drive died. Hopefully I diagnosed a bad hard drive correctly (I'll provide my method) and I hope this helps someone out there.
I have the same problem as well, it blinks but does not show up anywhere. I went to check in the System report and it was not there. What is the latest version of kodi. I have tried using a different cable and connecting it to another computer but neither works. I have some really important things on the drive so I would like to know a way in which I could get it working while still keeping all my previous files. My drive is a Seagate Backup Plus Portable Drive and the model is SRD00F1.