Files sync to Mac computers, but not to a Windows one

Hi RJWriter 

First thing to check is that Dropbox is running on all devices and not reporting any errors - mouse over its icon on the status bar to see what it says.

Next thing is that they are ALL using the exact same email and log on. A good way to test that is to add a file (a photo say) and see where it appears. 

In terms of syncing it should just do it as long as Dropbox is running without errors, on the same account AND its worth noting that files will ONLY sync to the Dropbox folder on the machine. So, if you work on a file elsewhere even if you copied/pasted it in to the Dropbox folder once that file wont update. The only way to update and sync is to work on files INSIDE of the \Dropbox directory.