Advertisements on web pages? That's so 2000. Ads in free mobile apps? Becoming a fact of life. But ads in file managers? That's probably pushing it a bit. Yet that is exactly what Microsoft seems to be doing to an increasing degree with File Explorer in Windows 10. No, you don't have to worry about NSFW content suddenly showing up. At the moment, it's just an ad, really nagware, for users to sign up for a premium OneDrive account. But Microsoft's nagware behavior this past years is causing some serious concern among users.