Can't find serial number on laptop that won't turn on

[silicon__9105]

My mom's laptop recently stopped working - I mean, it won't turn on, it isn't charging (no light turns on, nor does the laptop make any of the regular start up sounds) - it's completely dead. I have the same model laptop as my mom, and I've tried charging it with my charger cord on several different outlets in our apartment. I also noticed while trying to look for a serial number, I heard something loose inside her laptop rattle/roll around? i have no idea. 

I registered both laptops for warranty when we first got them, I'm able to see when the warranty for this laptop expires, so I'm 100% sure that her laptop is covered as well. The problem is that I can't find a serial code to register for HP feedback. The only way I was able to access the code for the laptop I'm currently posting this from is by logging in and going to the HP Support Assistant app. Mom's laptop won't turn on in order for me to access any of this information. 

i think we still have the box somewhere, but there's no serial number on the laptop any where. What should I do/where should I look? I just now signed up for an HP account. 

[WAWood]

@silicon__9105 

You need to do a couple of things:

1) create boot media to start PC

2) enter command to display SN

As to the first, you will need to create Boot Media using a working PC.

Macrium Reflect is a free tool that can be used to image and restore PCs, but it also has an option to create Rescue Media (in disk or USB form) that can then be used to bot and/or Repair your PC.

It is available from here: http://www.macrium.com/reflectfree.aspx

What I recommend is the following:
a) Download and install Macrium Reflect (MR)
b) Use the option to create a boot USB stick or CD
c) Boot your PC from the MR media -- it will take a while, so be patient!

As to the second, open a command prompt window by typing cmd into the search area.  At the commend prompt, enter the following command:  wmic bios get serialnumber

and then press Enter.

You’ll see the computer’s serial number displayed beneath the text “SerialNumber”. This command uses the Windows Management Instrumentation Command-line (WMIC) tool to pull the system’s serial number from its BIOS.