Thanks for the question. I understand that you are experiencing Wi-Fi connectivity issues with your iPhone 4s. It seems like you are on the right track, as you came from the following resource. Have you exhausted all of the troubleshooting steps suggested?
1. Be sure you're in range of your Wi-Fi router (access point).
2. Tap Settings > Wi-Fi and turn Wi-Fi off and on. If your W-Fi setting is dimmed, follow these steps.
3. Confirm that your Wi-Fi router and cable or DSL modem are connected to power, turned on, and connected to the Internet. If not, refer to your network administrator or Internet service provider (ISP) for assistance.
5. Tap Settings > Wi-Fi and locate the Wi-Fi network to which you're connected.
6. Tap and Forget this Network.
7. Try to connect to your desired Wi-Fi network.
Note: You may need to enter your Wi-Fi password again if your network requires one.
8. Turn your Wi-Fi router off and on. If your ISP also provides cable or phone service, check with them before attempting this step to avoid interruption of service.
9. Update your device to the latest version of software.
10. Update your Wi-Fi router to the latest firmware. For AirPort Base Stations, install updates using the AirPort Utility.
Unable to locate a Wi-Fi network
1. Verify that the network is available by tapping Settings > Wi-Fi and choosing from the available networks. Note: It may take a few seconds for the Wi-Fi network name to appear.
2. Move closer to your wireless router (access point) and attempt to locate the Wi-Fi network.
3. If you do not see the network you would like to join, you may be attempting to connect to a hidden network. Learn how to join a hidden network.
4. Supported Wi-Fi configurations vary by iOS device model. Find out which standards your device supports3.
5. Reset network settings by tapping Settings > General > Reset > Reset Network Settings. Note: This will reset all network settings including:
- previously connected Wi-Fi networks and passwords
- recently used Bluetooth accessories
- VPN and APN settings