Microsoft really wants you to upgrade OneDrive, with new ads popping up in Windows 10 File Explorer
Found on Digital Trends on Thursday, 09 March 2017

One of the least popular new “features” in Windows 10 is the advertising function Microsoft injected directly into the operating system. Ads show up in a number of ways, from promotions of Windows Store apps in the Start menu to pop-up “reminders” that Microsoft’s Edge browser gets better battery life than Google’s Chrome.
OneDrive is baked into Windows 10 and can’t easily be uninstalled, and Microsoft wants to make sure you know that the 5GB of free OneDrive storage can be easily upgraded to significantly more space.
Microsoft has not learned anything from their spam approach to force the adoption of Windows 10.