If you have a library that the OneDrive sync client cannot sync, the previous sync client will continue to sync that library. When you sign in to the OneDrive sync client (OneDrive.exe), the OneDrive sync client automatically takes over syncing the sites libraries that the previous OneDrive for Business sync client (Groove.exe) was syncing. Installation and setup guides for users are available for syncing OneDrive in Windows, OneDrive on Mac OS X, and SharePoint files on Windows and Mac. If you're ready now, download the new OneDrive sync client. This requirement doesn't apply to on-premises customers or customers with more than 250 Office 365 licenses. Office 365 customers with fewer than 250 Office 365 licenses are required to use the new OneDrive sync client to sync OneDrive for Business files.
The OneDrive sync client doesn't yet support syncing on-premises instances of OneDrive for Business or SharePoint Server (when your organization doesn't subscribe to an Office 365 business plan). The new OneDrive sync client supports Windows 10, Windows 8.1, Windows 8, and Windows 7.
