Many modern websites will fail to load due to outdated security certificates (SSL/TLS).
Force-restart the phone by holding the Power and Home buttons for 15 seconds until the Apple logo appears. Post-Downgrade Tips: Living on iOS 5
Download the official iOS 5.1.1 IPSW file for the iPhone 4S from a trusted repository like IPSW.me. Place this file on your desktop. Step 3: Put Your iPhone 4S into kDFU Mode
Which you are using (Mac, Windows, Linux)? Do you prefer a permanent downgrade or a dual-boot setup?
After downgrading to iOS 5:
Enter your iPhone’s when prompted by the Terminal.
: No baseband (no cellular calls). Wi-Fi works perfectly. This is best as an iPod touch running iOS 5.