"Erase all Content and Settings" not working

[nevergettinout]

Hello,

I am wanting to sell my iPhone but before I do so, I would like to wipe it clean of all my information. I tried restoring it in iTunes but I kept getting an error 3004 or else it said it could not connect to the server (or something along the lines of that).

So I figured if that will not work, I will "erase all content and settings" I have attempted this twice now: the first time was for 3hrs, the second time was for 12hrs. When I press the button I just get a loading wheel sign, no logo, no loading bar. After it taking so long I rebooted my phone and all the same content was still there.

How do I fix this?!

iphone details:
3GS 8GB
version 4.3.5
modem firmware 05.16.02
jailbroken with redsn0w for mac

Your help would be greatly appreciated,
Thank you!

 

[JunkyDog]

check your hostfile, and then try again..

 

[rw3]

Being Jailbroken is causing that feature to not work. You will need to DFU Restore in order to wipe the phone....

 

[nevergettinout]

Being Jailbroken is causing that feature to not work. You will need to DFU Restore in order to wipe the phone....

How do I DFU Restore? Like actually just go into DFU mode and click restore in iTunes?

 

[Crystal-RX]

How do I DFU Restore? Like actually just go into DFU mode and click restore in iTunes?

yes, that is correct. This will allow your iphone to restore to the most update firmware Apples is signing now.

 

[nevergettinout]

yes, that is correct. This will allow your iphone to restore to the most update firmware Apples is signing now.

I did it and I still am unable to restore. The message that pops up reads:
"The iPhone "iPhone" cannot be restored at this time because the iPhone software update server could not be contacted or is temporarily unavailable."
Is there anything I could possibly try out?

----------

check your hostfile, and then try again..

How do I access my host files, and what is the content supposed to look like?