how do i solve error with code 1015

This is what Apple has to say about error 1015.

"Error 1015: This error is typically caused by attempts to downgrade the software for an iPhone, iPad, or iPod touch. This can occur when you attempt to restore using an older .ipsw file. Downgrading to a previous version isn't supported. To resolve this issue, attempt to restore with the latest iPhone, iPad, or iPod touch software available from Apple. This error can also occur when an unauthorized modification of the iOS has occurred and you're now trying to restore to an authorized, default state."

1. Close iTunes.

2. Connect your iPhone to your computer and then launch iTunes.

3. Turn your iPhone off (hold down the power button at the top of the iPhone).

4. Then, hold down the sleep/wake button and home button together for EXACTLY 10 SECONDS, then release the sleep/wake button.

5. Continue to hold down the Home button until a message appears in iTunes telling you an iPhone in recover mode has been detected. When you are in DFU mode your iPhone screen will be completely black. Remember that if you see the restore logo, iTunes logo, or any message on the iPhone screen, you are not in DFU mode but standard Recovery Mode.

6. Hit the OK message that should popup to restore your phone. Restore as "New".

My directions are for DFU mode. If that doesn't work, there's not much more we can suggest you do.