I changed the computer and when I installed the Dropbox it started synching my entire computer (!!??) I selected selective sync as I only need one folder to be kept but this doesn't work. Now I run out of space. Sure I did when you sync what I did not ask you. Why selective sync is not working for my dropbox? I never asked to sync all the documents from my computer....!!!
I'm sorry to hear about this. It sounds like you enabled the automatic computer backup feature in the Dropbox desktop application. Could you first try disabling the computer backup from Dropbox using the steps in the above article to see if this helps?
Afterwards, you can move the folders and files back to their previous locations, which will also delete them from the Dropbox account online.
If you need any further assistance on this matter, please let me know.