My Windows 7 serial

Hi

Almost 3 years ago I bought my Dell M4700, and with it I also payed the OS (W7). The things is I lost the serial code for Windows (which is sometimes in a label under the laptop, not in mine though), and when formating I installed a pirate version of it.

Things is now WIndows asked me if I wanted to ugrade to windows 10 (which I want) but then it detected that my copy is pirate.

I guess I have the right to ask Dell to give me my serial number right? Cause I payed for it, so I guess I deserve having it back.

Just contacting technical support they will give it to me?

Thanks a lot.