TeraByte Unlimited

Hello,

I was backing up my data drive and it was taking too long to backup the drive (showing more than 15 hours which usually takes about 3-4 hours). I detached the external storage to which the data was being backed up and I found that my internal laptop data hdd disappeared. Need help and guidance to recover/unhide my data drive

sounds like your hard drive may have died. Could try power cycling, but if doesn't show up anywhere, it probably failed.