To use any of the options available within OneDrive, including the creation and editing of presentations using PowerPoint Online, you will have to first sign in with your Microsoft account. A Microsoft account is essentially your account on any of Microsoft’s services such as Hotmail, Outlook, Xbox, Skype, Live, Zune, etc. In this tutorial, we explain how you can sign in using any of these services into OneDrive.
Learn how to sign in to your OneDrive account.

