IPhone 4 ATT - Can't restore iPhone?

I just can't restore my iphone 4 for att I want to use. I've done different types of restore with shift restore with cutsom ISPW, tried jailbreaking restoring and turning off all my firewalls while doing the restore too. I get a error saying that i can't restore iPhone and a (-1) can anyone help me please? Show me a link to a vid or you can show me threw skype if your a tech expert.

Added (1). I have already put it in DFU mode and it still doesn't work. Anyone know a jailbreak that can restore my phone some how?

You have to put your iphone in dfu mode and then you can restore. If you try to restore when the phone is on then it won't work

go here and follow the instructions:-

http://www.iclarified.com/entry/index.php?enid=1034