Here is the story, i had iPhone 4S ( 7.0.4_11B554A ) in hands now. The WiFi suddenly not working, ive do factory reset within the phone and it does not solve the problem.
So i tried hard reset/restore using iTunes, connect my phone > click restore, and it does the downloads but after finished downloading, iTunes stated that the files downloaded is corrupted.
So then i tried the manual way, I downloaded the .IPSW file from apple server ( iPhone4,1_7.0.4_11B554a_Restore.ipsw ), when finished, i tried it and i received Unknown Error (14), halfway restoration stops, cant turn on my device, it stucks at recovery mode, and also tried in DFU mode, same error. I tried again with some readings on the net, found a programs named Object Fix, where it can run a test on IPSW file, its turns out its a bad CRC mismatch, and its true as i also converted the IPSW files to zip and turns out the same, CRC mismatch, or, Corrupted files.
After some more thorough reading, i found out that this is Apple's problem, some people managed to get clean ipsw files and some are not, need to continue try downloads the IPSW files until we get the uncorrupted one.
Now my phone stuck at Recovery mode ( iTunes logo with Cable ) cant turn on at all.
What i require a help for all of you is, Do anybody here managed to install iOS 7.0.4 on your 4S successfully using IPSW files?
If yes can i have that file? Or any other suggestion
Best is to try with another computer/lappie.
Make sure your iTunes is the updated version.
For the wifi problem, it's quite common for iPhone 4s. 5 out of 10 users faced this problem. It's due to wifi IC problem. To solve it will need to change this chip.