You can easily unlink your Windows computer from Dropbox Desktop Application. To do this, you need to download and install 'Dropbox Desktop Application' on your computer. It creates a folder (Dropbox folder) on your systems hard drive. Click 'Dropbox' icon located on your system tray and then 'Gear' icon. Select 'Preferences' and then select 'Account' tab. Click 'Unlink This Dropbox...' button to unlink the windows computer from Dropbox desktop application. When you unlink your computer, it will prompt your to sign in again.