How do I find my computer serial number on Windows 7?

When your Computer Turns On:

1. Open up the command prompt window on your computer. You can do this by searching for "cmd" or right-clicking on the windows home icon in the bottom left corner of the screen.
2. In the command window type in "wmic bios get serialnumber". The serial number will then be displayed.

When your Computer Doesn't Turn On:

1. If the command window can't be accessed, or the computer doesn't turn on, Dell Laptops also have the serial number printed on the laptop. Newer Dells like the XPS models have a flap on the bottom that can be lifted up to reveal the serial number.
2. If there is no flap, the serial number is still printed somewhere on the bottom case identified by the white sticker and bar code.
3. On Desktop models, the Serial Number sticker is usually placed either on top of the machine or on the back by the ports.