Where to find your serial number depends on your operating system

Your computer's serial number is a unique identifier printed by the manufacturer. On Windows machines, you can find it through System Information or by running a command. On a Mac, it's in About This Mac. On Linux, the location varies by distribution, but you can usually retrieve it through the terminal. The serial number matters when you need warranty service, file insurance claims, or prove ownership to your IT department.

The serial number is different from your device name (the nickname you gave your computer) or your Windows product key. It's a manufacturer-assigned code that stays the same throughout the computer's life, even if you reinstall the operating system or change users.

Key Takeaways

  • Windows users can find the serial number by opening System Information and looking for "System Serial Number" or by running the command wmic bios get serialnumber in Command Prompt.
  • Mac users can click the Apple menu, select About This Mac, and look for "Serial Number" in the System Report window.
  • Linux users can open a terminal and run sudo dmidecode -s system-serial-number to retrieve the serial number.
  • The physical serial number is also printed on a sticker on your computer's chassis, usually on the bottom or back panel.
  • You may need administrator or root access to retrieve the serial number through software on some systems.

Finding the serial number on Windows

The easiest method on Windows is to use System Information. Press the Windows key and type "System Information" into the search box, then open the application. In the window that appears, look for the line labeled "System Serial Number." This field contains your computer's unique identifier.

If System Information doesn't show the serial number (which happens on some older or custom-built machines), you can use Command Prompt instead. Right-click the Start menu and select "Windows Terminal (Admin)" or "Command Prompt (Admin)." Type wmic bios get serialnumber and press Enter. The serial number will appear on the next line. This method works on most Windows 10 and Windows 11 machines.

Some manufacturers also include the serial number in Device Manager. Right-click the Start menu, select Device Manager, and expand "System devices." Look for entries like "System board" or your computer's model name. Right-click and select Properties, then check the Details tab. Not all manufacturers populate this field, so it's not a reliable method on its own.

Finding the serial number on Mac

On a Mac, the serial number is in About This Mac. Click the Apple menu in the top-left corner of your screen and select "About This Mac." A window will open showing your Mac's basic information. Look for the line labeled "Serial Number" — this is your computer's unique identifier.

If you're running an older version of macOS, the serial number might appear under a different name or in a different location within the window. You can also access this information by going to System Preferences (or System Settings on newer Macs), then About, and looking for Serial Number in the same way.

For users who prefer the terminal, you can retrieve the serial number by opening Terminal (found in Applications > Utilities) and typing system_profiler SPHardwareDataType | grep "Serial". Press Enter and the serial number will display. This method is useful if you need to document the serial number in a script or automated process.

Finding the serial number on Linux

Linux systems store serial number information in the BIOS or firmware, which you can access through the terminal. Open a terminal window and run the command sudo dmidecode -s system-serial-number. You'll be prompted to enter your password (since this requires root access). The serial number will appear on the next line.

If that command doesn't work on your system, try cat /sys/class/dmi/id/product_serial instead. Some Linux distributions organize this information differently, so one of these two commands should work on most machines. If neither returns a result, your system may not have this information stored in a standard location, which sometimes happens with custom-built computers or certain laptop models.

You can also check the BIOS or UEFI settings directly by restarting your computer and entering the firmware menu (usually by pressing Delete, F2, F10, or F12 during startup, depending on your manufacturer). The serial number is often displayed on the main information screen, though navigating firmware menus varies widely between manufacturers.

Checking the physical serial number on your computer

The simplest method that works on any computer is to look for the physical serial number label. On most laptops, this sticker is on the bottom of the chassis. On desktop computers, it's usually on the back panel or sometimes on the side. The label typically includes the manufacturer's logo, model number, and a barcode alongside the serial number.

The serial number on the physical label is the same one you'll find in your operating system. This method doesn't require any software access and works even if your computer won't start up. If the label is worn or illegible, the software methods above are your next option.

Some manufacturers place the serial number in multiple locations on the chassis. If one label is damaged or missing, check the other sides of your computer. Ultrabooks and thin laptops sometimes have the serial number printed very small, so you may need a magnifying glass or good lighting to read it clearly.

What to do if you can't find the serial number

If none of the software methods return a serial number, your computer may be custom-built or assembled from parts without a manufacturer serial number in the standard location. This is common with gaming PCs, workstations, or computers built by local repair shops.

In this case, check the physical labels on individual components. The motherboard, power supply, or hard drive may have their own serial numbers, though these are not the same as the computer's system serial number. If you need a serial number for warranty or support purposes, contact the person or company that built your computer — they may have documentation from the original purchase.

For insurance or ownership documentation, you can also use your computer's MAC address (a network identifier) or the serial number of your hard drive as an alternative. These are less universal than a system serial number, but they can serve the same purpose of proving ownership or identifying your specific device.

Frequently Asked Questions

Is the serial number the same as the product key or license key?

No. The serial number is a manufacturer identifier for the physical hardware. The product key (on Windows) or license key is for the operating system software. You need the product key to reinstall Windows, but the serial number stays the same even if you replace the operating system entirely.

Can I change my computer's serial number?

Changing the serial number stored in firmware is possible but requires specialized tools and technical knowledge. For most users, the serial number is permanent. If you're trying to change it for legitimate reasons (like replacing a motherboard), contact the manufacturer or a certified repair technician.

Do I need the serial number to sell my computer?

It's a good idea to provide the serial number to a buyer so they can verify the computer's history and check for recalls. You should also document that you're transferring ownership. Some platforms for selling used computers ask for the serial number as part of the listing.

What if my computer has multiple serial numbers?

Your motherboard, hard drive, and other components each have their own serial numbers. When people refer to "the" serial number, they mean the system serial number assigned by the computer manufacturer. The others are component-level identifiers and serve different purposes.

Can I find the serial number if my computer won't turn on?

Yes. Check the physical label on the bottom or back of your computer. This is the most reliable method when the computer is not functioning. If the label is missing or illegible, you'll need to take the computer to a repair shop where technicians can access the BIOS or check component labels.