Where to find your serial number on Windows, Mac, and Linux

Your computer's serial number is a unique identifier printed or encoded by the manufacturer. On Windows machines, you can find it through the System Information tool without opening your computer. On Mac, it appears in the About This Mac window. On Linux, the location depends on your hardware manufacturer, but system tools like dmidecode or lshal can retrieve it if your BIOS stores it.

The serial number is not the same as your product key or device name. It's a factory-assigned code that manufacturers use to track warranty coverage, recalls, and hardware history. You may need it for warranty claims, insurance purposes, or when selling your computer.

Key Takeaways

  • Windows users can open System Information by pressing Windows key + R, typing msinfo32, and looking for the System Serial Number field.
  • Mac users can click the Apple menu, select About This Mac, and find the Serial Number listed in the Overview tab.
  • Linux users can open a terminal and run sudo dmidecode -s system-serial-number to retrieve the serial number from BIOS data.
  • Your serial number is also printed on a sticker on your computer's chassis, usually on the bottom or back panel.
  • Keep your serial number in a safe place if you plan to file a warranty claim or report your computer as stolen.

Finding the serial number on Windows 10 and 11

The fastest way on Windows is through System Information. Press the Windows key and R at the same time to open the Run dialog. Type msinfo32 and press Enter. A window will open showing your system details. Look for the field labeled System Serial Number — this is your computer's unique identifier. The number may be blank if your manufacturer did not store it in the BIOS, but most major brands (Dell, HP, Lenovo, ASUS) populate this field.

If System Information shows no serial number, check the physical sticker on your computer. Most machines have a label on the bottom, back panel, or inside the battery compartment. The sticker usually lists the model number, serial number, and other hardware details. Write down the serial number exactly as it appears — it may include letters and numbers.

Finding the serial number on Mac

On any Mac, click the Apple menu in the top-left corner and select About This Mac. A window will open showing your Mac's hardware information. In the Overview tab, you will see a field labeled Serial Number. This is your computer's unique identifier. Copy or write down the number exactly as shown.

If you are using an older Mac or need additional hardware details, you can also find the serial number by clicking System Report in the same About This Mac window. The serial number will appear in the Hardware Overview section. For MacBook models, the serial number is also printed on the bottom of the chassis near the regulatory information.

Finding the serial number on Linux

Linux does not have a built-in graphical tool like Windows or Mac, but you can retrieve the serial number from your system's BIOS data using the terminal. Open a terminal window and run the command sudo dmidecode -s system-serial-number. You will be prompted to enter your password. After you do, the system will display your serial number if the manufacturer stored it in the BIOS.

If dmidecode returns no result or is not installed on your system, try sudo lshal | grep system.hardware.serial instead. Some manufacturers do not populate the BIOS serial number field, so you may need to check the physical sticker on your computer's chassis. For laptops, this is usually on the bottom panel. For desktops, check the back or side panel.

Checking the physical sticker on your computer

Every computer has a manufacturer's label somewhere on the chassis. On laptops, this is almost always on the bottom panel. On desktop towers, check the back panel, side panel, or inside the case near the power supply. On all-in-one computers like iMacs, the label is usually on the back or bottom edge.

The label contains multiple pieces of information: the manufacturer name, model number, serial number, regulatory certifications, and sometimes a barcode. The serial number is typically labeled as S/N, Serial, or Serial Number. Write down the serial number exactly as printed, including any letters or dashes. This physical serial number is the most reliable source if your operating system does not display it.

What to do with your serial number once you have it

Store your serial number in a safe place. If your computer is stolen or lost, you can provide the serial number to law enforcement and your insurance company. Many manufacturers also use the serial number to verify warranty coverage, so keep it handy if you need to file a warranty claim or contact technical support.

Some people photograph or scan the label containing the serial number and store the image in cloud storage or email it to themselves. This way, you have a backup copy even if you lose the computer. If you are selling your computer, you may want to provide the serial number to the buyer so they can register it with the manufacturer or verify its history.

Frequently Asked Questions

Is the serial number the same as the product key?

No. The serial number is a unique hardware identifier assigned by the manufacturer. The product key is a software license code for Windows or other operating systems. You need the product key to set up Windows, but the serial number is used for warranty and hardware tracking.

What if my computer does not show a serial number in System Information?

Some manufacturers do not store the serial number in the BIOS, so it will not appear in System Information or terminal commands. In this case, check the physical sticker on your computer's chassis. The sticker always has the serial number printed on it, even if the software does not display it.

Can I change my computer's serial number?

The serial number stored in your BIOS can be modified with specialized tools, but this is not recommended and may void your warranty. The physical serial number printed on the label cannot be changed without physically altering the label. For most purposes, you should use the serial number as the manufacturer assigned it.

Do I need the serial number to return my computer for repair?

Most manufacturers ask for the serial number when you contact them for warranty service or repairs. Having it ready speeds up the process. If you cannot find it, the manufacturer can sometimes look up your account using your email address or phone number, but providing the serial number is faster.

Where is the serial number on a laptop versus a desktop?

On laptops, the serial number sticker is almost always on the bottom panel. On desktop towers, check the back panel, side panel, or inside the case. On all-in-one computers, the label is usually on the back or bottom edge. If you cannot find a physical sticker, use your operating system's tools to retrieve it.