Multitasking, folders, wallpapers, and more, oh my! The wait is over, version 4.0 of iOS is available as a free download for compatible iPhone and iPod Touch devices. For those who recently bought iPhone 4, the new OS will come pre-installed when it ships later this week.
Download iPhone OS 4.0
You can download iPhone OS 4 directly from iTunes. To install the update, all you need to do is connect your iPhone or iPod Touch to your computer with iTunes open. iTunes will notify you when OS 4.0 is available and you will be able to download the software and update your device. Remember that prior to installing iOS 4 on your iPhone / iPod you will need to have downloaded and installed iTunes 9.2 as a prerequisite.
If iTunes does not notify you automatically of the iPhone OS 4 update being available, just click on the ‘Update’ button under the ‘Summary’ tab after you have selected your iPhone within iTunes, this will start the update and download process as well.
It’s always a good idea to backup your iPhone before installing any updates.
If you’re having problems, advanced users can also download iPhone IPSW directly from Apple. This is not recommended for novice computer users.
iPhone OS 4.0 Compatibility
iPhone OS 4 (more accurately, iOS 4) is compatible with iPhone 4, iPhone 3GS, iPhone 3G, and the 2nd and 3rd generation of iPod Touch devices. The feature set degrades on older devices, and the ability to multitask and change background pictures will not function on iPod Touch 2nd Gen or iPhone 3G, the original iPhone 2G doesn’t get the update at all.
The updated iOS 4 for iPad has the same feature set but will be made available in the fall. If you are interested, you can read more about the popular iOS 4 features.