In Windows 10, old File Explorer favorites are now pinned under Quick access in the left side of File Explorer. If they're not all there, check your old favorites folder (C:\Users\username\Links). When you find one, press and hold (or right-click) it and select Pin to Quick access.
![](https://support.content.office.net/en-us/media/80b04b46-0dcf-44a2-868f-29e3b50f475a.png)