Someone is erasing your stuff man. I've never had a single issue with it and I got a 2 tb harddrive on my wii u and xbone.

Buy a new one.

If theres a fault in the drive that made it lose the filesystem, which in turn made it look like everything was just gone... the same thing could happend again.

Would suck if you redownloaded & installed everything and a few months from now you have the same issue.

^ Ive had this issue with a internal HDD before. When something like that happends you get a new drive instead, of useing the old damaged one.

Especially if its about important stuff, like saveing your games you care about.

A hard drive works by haveing a filesystem, that says "find this part of data here, location such and such".

If your filesystem is damaged/currupted/lost, HDD might just make a new clean one, which in turn would make the drive appear to be empty.

Its technically not, but unless he wants to spend forever trying to recover it, it might as well be.

The problem is if his hard drive is failing, just ignoreing the fact that it did this once already, isnt gonna solve his issues. Its likely to happend again.

I have a Seagate 2TB hooked up to mine, works like a dream.

Why would it be impossible?
Connect it to a PC. Right click on Computer, select Manage, then Disk Management and the HDD should be listed there, ready to be reformatted.
If it isn't listed there, either download and use Partition Wizard or use Windows' own command-line.

I tried quite extensively to get my PC to acknowledge it exists about a year ago, I'll give it another go but it certainly doesn't show up in Disk Management or other Applications I downloaded at the time.

A google search came up with no solutions back then either.

I am pleased to tell you that, formatting a HDD or SSD for use with a WiiU will not result in your drive being unusable.
The problem if indeed there is truly one, would likely be the fault of your OS or your use of your OS.
If you cannot use Microsoft Windows to do the job, use a Linux distro, you can boot a wide selection of Linux distros from a USB, meaning that you would not be required to install it on your main system.
Give Linux a try, personally I recommend using a Debian based system with the GNOME desktop environment.

That's an absolute joke, If the HDD isn't easily reformatable Nintendo screwed up. I'll give it a go on windows first then followed by linux and post my findings here.

I had no trouble reformatting my drive in OSX. Don't know about Windows systems, but it might be something wierd that is specific to your setup.

If that were truly the case then it would be due to the HDD's ICs or internal management of data, after a decade of service errors are not altogether unavoidable.

If you need any help with Linux I am happy to be of assistance.