How to fix Error 0x8007045D?

Hey guys i was trying to transfer couple of my files to my external hard and suddenly the computer crashed. now i cant open a single file in there and it says there is an I/O devise error and the error number was 0x8007045D. i tried restoring my computer and even tried another computer but didn't worked. certain data of my thesis is in there and those will take weeks to simulate again. i tried doing chkdsk but it says the file system is raw and it cant do raw. please guys help me on this