Problems with external WD Elements after installation in desktop

I have a WD Elements 5TB as an external drive and have put lots of stuff there, but after plugging it in within my desktop to use it as an internal drive, it requires me to format it before use. But I have lots of stuff on it. Is there a away to populate it, or can I install it externally again and transfer the files via USB to other drives before I install it as an internal drive again?


You can try using a data recovery software to get the files out of the drive.