Believe it or not, Siri on your new iPhone 4S does not come pre-enabled. So if you press and hold he home button on your iPhone 4S and Siri does not pop up, don’t be surprised. It needs to be turned on. By default, Apple’s Voice Control system is the one that is enabled, not Siri.
So follow these steps and Siri will be made available to help you.
1. Go to Settings
2. Tap on General
3. Tap on Siri
4. Slide the switch to ‘On’.
You can also choose other Siri settings like “your info” and “raise to speak”. Similarly if you don’t like the humble new personal assistant, you can turn in off by following the above simple steps.