Hard Disk Is Not Initialized & Gives Data Error-Cyclic Redundancy Check?

Situation1: Hello, I do have used a Toshiba internal hard disk on my Samsung computer and recently it becomes really strange. It is not found in My Computer and also shows an unknown not initialized drive in Disk Management. When I try to initialize it there, an error message just pops out and says:"…data error cyclic redundancy check…" Please help me out. This drive really still contains much important computer data yet! Thank you in advance!