Hardrive suddenly unallocated

[woofercooker]

One of my external usb caddy hardrives suddenly stopped showing up, i went into disck manager and noticed it was listed as unallocated, i assumed it had failed, i downloded a program at random diskdrill to see if i could recover any files and that program brough up litteraly everything no problems at all, its just like browsing my hardrive as if nothing happend. I need to but the full version of the product and another hardrive to recover everything too but any idea what caused this and is there a way to recover to the same hardrive or do you need a new one, there isn't really any imporant data i need but i would still like to keep the stuff on there if i can, its just stuff i've downloaded which could easily be downloaded again but id like to still try and see if i can still save the drive is possible.

 

[paul10]

exactly the same issue as you unallocated drive wd duo 20tb except when i used diskdrill it found a load of stuff on top that i had deleted ,so instead of the 6tb i thought i had it actually resulted in 12tb at first i thought it was because i had raid 1 array set up on my external drive but no it has found a mass of deleted removed folders that i thought i had removed a real pita ,spent 36hrs recovery on to a qnap das 36tb set ,it may have been a hack or malware that caused the issue i also noted i had a corrupted windows code with a transulcent mask in the corner of my pc ask for windows update or something of this description.previous to this i had done two bios updates for my motherboard flash usb ones this resulted in me requiring a boot up and change of windows password pin