In what seems to be a completely out of the blue and unheard of move which seems to validate a lot of fears about Windows 10, Microsoft is using Windows Explorer as an advertising platform. Here is a screenshot from one of our own systems:
You can change it by going to View --> Options --> View and untick "Show sync provider notifications".
It's not very clear what this will disable, but it seems to stop the ad.
This is completely ridiculous and a stupid move by Microsoft, while they literally gain nothing from it except notoriety. It seems to be one step ahead, two steps back all the time.
Hopefully there will sufficient outcry for them to stop this kind of invasive advertising. The ad itself isn't anything particularly weird or threatening in the technical level, it is its very existence that is a cause for concern though, because it touches the "holiest of the holies" of the traditional Windows desktop, which is the My Computer view of Explorer. Something that will freak out people even more about Microsoft's eventual plans for the traditional desktop.