Restore Errors/20xx

Error 2001

 * The Mac OS X kernel extension "IOUSBFamily" that was bundled with late 2008 / early 2009 MacBooks, as well as the 10.5.6 update, has a bug where it fails to properly recognize an iDevice in DFU Mode. It can be resolved by updating to 10.5.7 (or later), or using a USB hub.
 * Close limera1n.

Error 2002
iTunes can't connect because another program is using it or it's disconnected during the Apple Server check.

Error 2003

 * Connection problem; change USB cable and check USB port.
 * sn0wbreeze failed to restore IPSW; unplug and plug iDevice and try again

Error 2005
Problem connecting. Probably a hardware failure.

Error 2006
Replace the USB cable with a newer one and/or disconnect all other USB devices, then retry.