No, in fact you dont need to use it at all if you dont want to. Its purely optional. If you choose not to you still can play the game without anything missing from it, all the features that were there are there, nothings taken out. The service itself is a website, if you want to use it and register you enjoy the additional benefits.
On a side note: I hope they finally remove Windows Live from the Resident Evil games, its been dragging them down all this time, one of the rare titles that still uses it.