Not sure where you are now in trying to fix this? What was the Error # and message?
Lets start over. Reset, Hold both Home and Power Buttons until the iPhone begins to restart.
If nothing, connect to Wall Charger for at least 10 minutes, the iPhone may start on own and be fine. If not, keep connected to Wall Charger and Reset again. If still problem you may need to Restore the iPhone Firmware.
If you decide to Restore Firmware. With iTunes open connect iPhone to Computer. Hold both Home and Power buttons until iTunes recognizes iPhone in Recovery Mode. This usually take 20 seconds. Restore Firmware.
If this does not work then try DFU Mode Restore.
If still problems and you have Warranty or AppleCare Coverage take iPhone to Apple for resolution.