Unfortunately you haven't answered my previous questions, to help explain why you originally reported that there was no USB full disk erase function in Seatools. I checked and Seatools for Windows starting with v188.8.131.52 does
have that functionality under the Advanced Tests -> USB Erase Tracks menu. You seem to have now found this, but there's no explanation about why you previously denied its existance...
I encountered a problem - the drive status showed USB Full Disc Erase Failed. I tried a couple of times but still failed. Any ideas ?
That confirms how faulty the drive is.
Depending on how long the process ran before reporting a failure, and depending on the result of manual checks (e.g. with a hex editor), then we don't know how much of the disk (if any) was actually erased (overwritten). Unfortunately there aren't enough details in that error message to know exactly
what is happening.
said, there are other programs available for trying
to erase disks - although those may also fail, if the disk is really faulty. Be careful that you understand how to use any erasure tool which you decide to try, since you don't want to erase the wrong disk. For that reason, one safe technique (which might be outside your skill set), is to disconnect all internal disks, use a bootable CD (e.g. Linux or other tools) with disk erasure functionality, and the only disk which is attached is the disk to be erased.
You might end up having to make a choice, depending on the sensitivity of data that you've already stored on that disk: Either be certain that the disk cannot be read by anyone else by destroying the platters yourself - but then you cannot claim on the disk warranty (of course); or do what you can to erase the disk (if necessary by using some local PC help, since we can't see exactly what is happening to your desk through a web forum), and hope
that this is enough to prevent any curious person trying to look at that data, before the disk is repaired or destroyed later, by (or on behalf of) Seagate.
there are many freely available tools out there to wipe your drive clean.
True - unfortunately some (e.g. HDDErase) cannot be used with an external USB disk, as in this case. So the OP needs to ensure that they're trying to use appropriate s/w and, based on the results so far, I'm concerned that any tool trying to do overwrites of this USB-attached disk, may fail in a similar way - but my concerns might be overly pessamistic. I hope the OP appreciates your useful suggestions.
Even a full format (not 'quick') in Windows should do the job.
Unfortunately that's not true using your exact phrase, as it places no limits on versions of Windows to which it applies.
Just to be clear for other readers, your comment only
applies using a "full" format in Vista & Win7 (not WinXP and earlier versions). It also requires the user to understand a little about partitioning, and the difference between what a Windows drive letter represents (and hence, what gets overwritten), compared to a physical disk. Otherwise the end result (of what gets overwritten), might not be what they expect.