When I immediately open it and start the phone it let me update the phone to the new OS but it was not successful and still has it's own OS and ended up having a full memory.
Back up your iPhone 4S either via iCloud, iTunes or both. Afterwards, put the iPhone in recovery or DFU mode, connect it to your computer and then when the computer's iTunes app detects the iPhone in recovery, select to restore and update. Be sure the computer is connected to the Internet.