Bluetooth was optional upgrade on the Inspiron 660s. Did your PC come with that upgrade? If not, the easiest way to get Bluetooth is using a USB>Bluetooth adapter and pair it with the Echo as an external speaker and other sites which also detail how to do this. There are lots of choices for BT adapters. Just make sure the adapter supports your version of Windows and the version(s) of BT supported by your specific Echo model...
Is it possible to connect an 'echo' as a speaker via Bluetooth to this model dell desktop? Can a speaker such as 'Echo" be connected with a 'wire' (USB), if I cannot use Bluetooth? Are there desktops that have NO Bluetooth possible  nomatter what  drivers you try download?
Do all dell desktops have Bluetooth Capacity; Optimum 660s??