Open up to C:\Windows\System32\drivers\etc\ and open the 'host' file. Use Notepad to edit it. Remove any and all gs.apple.com lines in there. Save your changes. Next Start > CMD > and run 'ipconfig /flushdns' without the apostrophes. Do this with iTunes closed. Place the device into DFU mode, and shift + click the Restore button and point it to a fresh copy of 7.0.4. Since you're on the 4S, your IPSW must be named iPhone4,1_7.0.4_11B554a_Restore.IPSW. No other IPSW will work. If you're using a USB hub, a monitor, or the front USB ports on your computer, unplug the hub if applicable, and plug your phone directly to the rear of the unit. Then retry.