Maybe you’re noticed that iOS update to version 5.1 which contains improvements and bug fixes since the new iPad (iPad 3) has been released. And this tutorial describes How to download and install iOS 5.1 on iPhone 4s.
iPhone 4s Update To iOS 5.1
1. Turn on and turn on Wifi in your iPhone 4s and tap on Settings icon.
iPhone 4s Home Screen
2. Tap on General menu.
iPhone 4s Settings Screen
3. Tap on Software Update.
iPhone 4S General Software Update
4. Your iPhone will automatically check for an update, then display a screen similar to below:
iPhone 4s Download And Install New Update
… tap on Download and Install button.
5. It will estimate time remaining to download and install the update. It depends on your Wifi connection speed.
iPhone 4s Downloading Update
It may take up to few hours to finish downloading and updating iOS. After that, your iPhone will be reboot and you’re done 
In order to verify your software, go to Settings => General => Software Update again, your screen should display: iOS 5.1 – Your software is up to date.
iPhone 4s Software Up To Date
Significant Improvements in iPhone 4s iOS 5.1
There are many improvements and bug fixes in iOS 5.1, but I just see a few:
- 1. Battery lives longer. With iOS 5.0.1, I have to charge every 1.5 or 2 days. With iOS 5.1, it lives up to 3-4 days for normal use (no game, video, 3g, etc)
- 2. Camera shortcut now always visible on Lock Screen
- 3. 3G runs faster and more stable.
You can read through list of improvements and bug fixes from Apple below:
• Japanese language support for Siri (availability may be limited during initial rollout)
• Photos can now be deleted from Photo Stream
• Camera shortcut now always visible on Lock Screen for iPhone 4S, iPhone 4, iPhone 3GS and iPod touch (4th generation)
• Camera face detection now highlights all detected faces
• Redesigned Camera app for iPad
• Genius Mixes and Genius playlists for iTunes Match subscribers
• Audio for TV shows and movies on iPad optimized to sound louder and clearer
• Podcast controls for playback speed and a 30 second rewind for iPad
• Updated AT&T network indicator
• Addresses bugs affecting battery life
• Fixes an issue that occasionally caused audio to drop for outgoing callsFor information on the security content of this update, please visit this website:
http://support.apple.com/kb/HT1222
Note: after installing the new iOS, Cydia and Jailbreak softwares will be gone and you may need to wait to Jailbreak your iPhone again.
Install iOS 5.1 for your iPhone 4s With iTunes
Open iTunes and plug your iPhone in your computer/laptop then click Check for Update. Actually, it will check for update automatically and you may just follow their instructions to update to the latest iOS version.
iPhone 4s Update iOS software With iTunes
