Bob recently bought a new hard drive and wants to copy the contents of his older hard drive. Somehow, he lost the partition on the original drive. He's wondering if he can restore that data from the partition. Leo says no. Losing the partition is far more significant, and once a drive has been repartitioned, no data can be recovered.
Doug in the chatroom says TestDisk may be able to recover and undelete a partition. There's also Recuva by Piraform, which the chatroom says is easier to use. Partition Recovery from DiskInternals, and EaseUS Data Recovery Wizard are other options.