Windows 8.1 in its current state requires that you log in using an online account always [1] and provisions a SkyDrive account on login. However, even if you circumvent this or start with a local account (see [1] again), you will be signed into SkyDrive the moment you log into the windows store or any other app.
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Is this on the vanilla/out-of-the-box Win8.1 or only after you've installed the SkyDrive app or tweaked settings?
EDIT: assume you only need to sign up for a SkyDrive account. All of the desktop integration is enabled by default.
Windows 8.1 in its current state requires that you log in using an online account always [1] and provisions a SkyDrive account on login. However, even if you circumvent this or start with a local account (see [1] again), you will be signed into SkyDrive the moment you log into the windows store or any other app.
[1] This is apparently being removed in RTM.