Summary
In order to use most Apple services, including iCloud, every Apple products user must create an Apple ID. If you buy a new Apple device with the latest version of iOS or OS X, it will prompt you to sign in to iCloud with your existing Apple ID or create one. If you already have any Apple devices, make sure they have the latest version of the operating system and supports iCloud.
For Windows PC users, check if your PC meets the requirements and then install iCloud Control Panel. You can't create a new Apple ID or iCloud account on Control Panel. You must create it on an Apple device, whether it's a Mac or an iOS device (iPhone, iPad, and iPod touch).
