iphone 3gs error (9)

This error occurs when the phone unexpectedly drops off of the USB bus and communication stops. This can occur if your phone is manually disconnected during the restore process. This issue can be resolved by performing USB isolation troubleshooting, using a different USB dock connector cable, trying another USB port, restoring on another computer, or by eliminating conflicts from third-party security software. So, disable all your firewalls, any anti-virus, or anti-anything. Make sure you're using a 2.0 port directly on your computer & that your cable is good. Try again.

This is Apple's support document, that covers that error code:

http://support.apple.com/kb/TS1275

However, it is most often related to USB problems, bad port, bad cable, usb hub, etc.

Have you followed ALL the steps in the support document I referenced you? Including third party security software as outlined here:

http://support.apple.com/kb/TS3125