In May, at an education-focused event, Microsoft announced a new version of its operating system, called Windows 10 S. Pre-installed on the new Surface Laptop, the main feature is that it can only install apps from the Windows Store, adding a layer of security to the OS.
It does come with some non-Store apps pre-installed though, such as the OneDrive sync client, and that's where it begins to run into problems. This is because while you can uninstall the client on Windows 10 S, you can't download and reinstall it, leaving your only option to get it back as a factory reset, or an upgrade to Windows 10 Pro.
This shouldn't be a big deal for many, since there aren't many reasons to actually uninstall OneDrive, unless you don't use it and you want to free up that bit of space. Just be aware though, that as it stands right now, if you do remove it, you can't easily get it back.
It seems like it would be more of an issue for Microsoft, as those that uninstall it thinking that they'll never use it would be less likely to change their minds with a bigger barrier of entry.
Update: One of our readers found some workarounds for installing the sync client (other than doing a factory reset). You can actually bypass the screen that you see above by turning off your internet connection. Unfortunately, this won't work for other apps, such as Google Chrome.