I installed dropbox, but unable to sync with "Document" and "Desktop" on my PC @ i am getting the error " Can't back up to both one drive and dropbox. I deleted onedrive from my system and tried reinstalling dropbox but no luck. I appreciate your help in advance!
That wouldn't be relevant to the errors that you're getting when trying to set up the backup, what you mentioned is due to the Downloads not syncing when downloading files from Microsoft Edge once the backup is fully set up.
Do you possibly have the contents of these folders (Desktop and Documents) within OneDrive still or are they in their original locations on your computer?