iPhone 3G iOS 4 Jailbreak with RedSn0w. Unable to recognise IPSW [HELP]

[iMacBoy]

Hey,
So im attempting to Jailbreak my iPhone 3G iOS4
And im using RedSn0w.
I have downloaded the correct ipsw file according to a tutorial and it says Unable to recognise ipsw file.

Can anyone tell me what the problem is?

Thanks

 

[baller1308]

What version of redsn0w are you using?

 

[Neolithium]

Use the latest version of redsn0w.
Mac
Windows

And the official iOS4 IPSW
iOS4 for iPhone 3G

 

[thelatinist]

Either you have the wrong ipsw or you have the wrong version of redsn0w. Follow the advice in Neolithium's post.