What came before. Devices running older versions of macOS (before Mavericks) or iOS (below 7) may be unable to sign into iCloud after the iCloud password has been changed: the only resolution for this issue is to upgrade the OS, which may be impossible on a device that does not meet the newer OS minimum requirements.
Conversation transcript:
[+] Where are the ICloud data centers?.
[+] Also it was reported that Apple was going to relocate all of its services employees to the Apple Campus (1 Infinite Loop, Cupertino, California), as many other employees would be moving to the Apple Park..
[+] What are the system requirements for ICloud?.
[+] iCloud account creation requires either an iOS device running iOS 5 or later or a Mac running OS X Lion v10.7.5 or later, as well as an internet connection and a compatible web browser..
[+] Is ICloud available on Windows?.
[+] Also, certain features have their own minimum requirements of OS versions..
[+] What features of ICloud are available on Windows?.
[+] For example, using iCloud Photo Sharing requires OS X Mavericks v10.9 or above on a Mac..
[+] Are there any other system requirements for ICloud?.
[+] 