can't log into icloud on new windows laptop using existing apple ID
I've just bought a new windows laptop and it's not recognising my apple id when I try to log into icloud.
I have an iPhone X, an iPad Air 2 and I currently use my apple id on these with no problem.
I've also just set up iTunes on my new laptop using my Apple ID and password with no problem.
I always assumed that my Apple ID was the same as my iCloud ID. Is this correct?
I thought about re-setting my Apple ID password but I'd then have to change it on all my other devices which seems wrong if they're currently working.
Windows, Windows 10