[KFCLover]

So my friend asked for my help to fix his iPod 4g. He was going to restore it until there was a unexpected error. So I know when error 21 appears, a host might be blocking iTunes from restoring his iPod. But when I deleted the host and saved the file, error 21 still occurs. And it doesn't show his device name either
http://prntscr.com/2z6648 🤮
And I run it in DFU mode too

What should I do?