Do not sync entire project folders to your local machine unless you are actively editing them. Use Smart Sync to set everything to "Online-only" by default. The files look like they are on your PC, but they aren't. This keeps your C: drive clean and speeds up system searches (Windows Search won't index 10,000 online-only files unless you ask it to).
Common issues with the Dropbox PC app include: dropbox pc app
: Drag and drop existing documents into the new Dropbox folder to begin the initial sync. Do not sync entire project folders to your