HDD Not Exist

Hi,

I have a Hikvision NVR with a Seagate 2TB hard drive (Green). I've had this for two years without any issue. However, yesterday I had two power cuts and since then the NVR isn't recording as the HDD is seen as Not Exist. I have tried to format it but it doesn't do anything.

I try to connect this HDD to the laptop although it recognises it, I can't not see the drive for it.