If you didn't get the tracking device when you purchased the laptop, you won't be able to track it.
EDIT: Wait, there might be one way, but most likely won't work. A few Dell services require the laptop's serial number. If someone tries to access Dell support using the laptop, and they enter the serial number to the site, then Dell may be able to track their approximate location. This most likely won't work because Dell probably does not offer these kinds of services, whoever took your laptop probably won't go on the support website, and even if it does work, it's just only going to tell you what city your laptop is in.