Q: regarding update errors iphone 4s

is your iPhone hacked?

You would know when it was hacked, so it probably is not:

Read this set of helps:

http://support.apple.com/kb/TS1372

Don't worry that your code 3004 is not on the list.

Look at the error types and choose the one that you get, then read that article .

I told you, 3004 is not there in the list, but one of the links on that page tells you how to solve it (hacked phones can not be updated).