Why did you try to reformat???
Did this solve your problem?
Sorry this didn't help.
Great! Thanks for marking this as the answer.
How satisfied are you with this reply?
Thanks for your feedback, it helps us improve the site.
How satisfied are you with this response?
Thanks for your feedback.
Because my harddrive is unforatted and so I tried to format it but when I do it says it can't.
Is it a genuine Microsoft hard drive for the 360?
You will have to contact support. Your issue is listed here.
Scroll down to the I’m being prompted to format my hard drive section.