How to unlock my iPhone 4 after it locked from trying to download iOS 6?

I have an iPhone 4 and connected it to my HP laptop to sync. The pop up message appeared asking if I wanted to update to iOS 6. I clicked yes. I came back to my computer a few minutes later and there was a message saying an "unknown problem" occurred with the download and didn't work. Now my phone only has the screen with the cord and iTunes symbol. It refuses to reboot whatever I do and iTunes on the computer doesn't recognize when I hook my iPhone to the USB port. I've done searches on line and have yet to see anyone else address this problem. I can't be the only one.

Take it to the apple store or where you got the phone from

U probably can't go back but you can upgrade through mac. But if you want to unlock it you can do it through appenberry (google it) and pay $70 for it. But now you can't get out from restpring mode unless you restore it or update that takes away the unlock. I make no sense.

I have unlocked my iPhone 4 using the remote method of unlocking.
you can get the remote unlock services from the online site
http://www.mobile-unlocker.com and unlock it easily. You can
try this site for unlocking it is the best one.