Drive letter gone after "write zeros"

My 500gb WD external drive was nearly full, 3 times larger then my internal drive. Running my virus program would take all day. Tried to delete old files be couldn’t so I ran the the “write zeros” and now the drive doesn’t have an assigned letter. The drive does show up in the divice manager. Did I do something wrong and if so how should I have deleted all the old duplicate files?

Go into the Disk Manager and see if you can give it a drive letter.


Under “Disk Management” It shows under Disk 2 - Unknown 465.76 GB, Not Initialized and in the box next to that 465.76 GB Unallocated - I don’t know how to assign it a letter!