iCloud requires iOS 5 or later on an iPhone 4 or later ; a Mac computer with OS X Lion; or a PC with Windows Vista or Windows 7 (Outlook 2007 or 2010 or an up-to-date browser is required for accessing email, contacts and calendars). Some features require a Wi-Fi connection. Some features are not available in all countries. Access to some services is limited to 10 devices.
iCloud is only available on a device using software version iOS5 or later. To determine the device software version, refer to View Software Version.