As a first step, since the desktop app's startup may be blocked by a third party app like a security program, could you please temporarily disable your antivirus and ensure that you've configured your firewall to work with Dropbox?
As a first step, since the desktop app's startup may be blocked by a third party app like a security program, could you please temporarily disable your antivirus and ensure that you've configured your firewall to work with Dropbox?