Which online service allows you to store and retrieve files over the Internet?

Windows Future Storage is not a recognized Microsoft online service for file storage.

Windows Live SkyDrive was Microsoft's initial branding for its cloud storage service, which later evolved into OneDrive, specifically designed for storing and retrieving files over the internet. This service provides personal online storage accessible from various devices.

Windows Media Center was a media player and entertainment application, not an online file storage service.

Windows Storage Server is a server operating system designed for file and print sharing within a local network, not a personal online cloud storage service.