Hi Konan,
We regret the inconvenience caused to you. As you mentioned that the external hard drive is brand new and is not working, please click http://dell.to/UrR94G and update the driver for USB 3.0
Also, I would suggest you to connect the hard drive in a different USB port of your XPS 15 laptop. Also, try connecting the same in a different system if possible as it would be a good way to isolate the issue. If the hard drive works fine in a different computer, then the issue is with your laptop.
When you call tech support, the IVR prompts you to enter the service tag of your Dell product. As the external hard drive does not have a Service Tag or Express service code, you can enter the Service Tag of your Dell computer itself. The link mentioned below would give you details on where to locate the service tag on a Dell product.
http://dell.to/W8V8DA
If you would like me to assist you in this regard, please email me your computer’s Service tag at v_saini@dell.com
Do mentioned your name as it appears on the account so that I can check your system details and help you in the best possible manner.
However, if you would like to call Technical support, you can enter your computer’s Service Tag in the IVR and when you speak to the representative, let them know about the issue you are facing with the external hard drive. They would ask you to provide the order number for the external hard drive which you would have received in an order confirmation email at the time of purchase.
Thanks & Regards
Vishal S