how do i restore my device because my screen says device unknown

Hello, lanaziamarie.

Thank you for visiting Apple Support Communities.

When experiencing issues restoring or updating an iPhone, here are the best articles to go through. If you received a specific error number when restoring, see the section labeled Get more help in the second article below.

If you can't update or restore your iOS device

http://support.apple.com/kb/ht1808

Resolve iOS update and restore errors in iTunes

http://support.apple.com/kb/ts1275

Cheers,

Jason H.