Although the instructions in the links below are for Apple devices, the same basic steps should apply to your Windows 7 machine.
http://appletoolbox.com/2015/09/icloud-keeps-asking-for-password-ios-and-os-x-fix/
or
https://drfone.wondershare.com/icloud/get-rid-of-the-repeated-icloud-sign-in-request.html
Hope this helps.
Grif
I get these annoying incessant prompts (2) on my Windows 7 Pro workstation, I type in password and it does not accept even though it is correct. I use the same password on ipad and iphone and it works ok. How do I stop that stupid prompt every five minutes?
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic