Where to find your computer's serial number

Your computer's serial number is a unique identifier printed or engraved on your machine. The location depends on whether you have a desktop or laptop, and what brand you own. For most laptops, the serial number is on a sticker on the bottom of the case or inside the battery compartment. On desktops, check the back or side panel. Some manufacturers also print it on the original box or paperwork that came with the computer.

If you cannot find a physical sticker, the serial number is also stored in your computer's system information, which you can view without opening anything or looking for labels. This digital method works the same way whether your machine is brand new or several years old.

Key Takeaways

  • Your computer's serial number is usually a sticker on the bottom of a laptop or the back of a desktop, but you can also find it in system settings without moving the machine.
  • Windows computers store the serial number in System Information, which you can open by typing "msinfo32" into the search box.
  • Mac computers show the serial number in About This Mac, found under the Apple menu in the top left corner.
  • You may need your serial number for warranty claims, repairs, or to prove ownership if your computer is lost or stolen.
  • Write down or photograph your serial number and keep it in a safe place separate from the computer itself.

Finding the serial number on Windows

The fastest way to find your serial number on Windows is through System Information. Click the Windows Start button (the four squares in the bottom left), then type "msinfo32" into the search box and press Enter. A window will open showing your computer's details. Look for the line labeled "System Serial Number" — this is your unique identifier.

If System Information does not show a serial number in that field, try looking for "Product ID" instead, though this is different from a true serial number. Some manufacturers also store the serial number under a different name depending on the brand. If you are unsure whether what you are seeing is correct, compare it to any sticker on the physical machine to confirm they match.

Finding the serial number on Mac

On a Mac, click the Apple menu in the top left corner of your screen and select "About This Mac." A window will open showing your computer's information. Look for "Serial Number" in the list — it will be a string of letters and numbers specific to your machine. This is the same serial number printed on a sticker underneath your Mac laptop or on the back of a desktop.

If you do not see it in the main window, click the "System Report" button to open more detailed information. The serial number will appear there as well. Write it down or take a screenshot so you have it saved in case you need it later.

Finding the serial number on Linux

Linux computers do not always have a manufacturer serial number stored in the system the way Windows and Mac do. However, you can still find it by opening a terminal and typing the command sudo dmidecode -s system-serial-number, then pressing Enter. You may be asked for your password. The serial number will appear on the next line.

If that command does not return a result, your computer may not have a serial number stored in the firmware. In that case, check for a physical sticker on the case. If you built the computer yourself or it is a custom machine, it may not have a manufacturer serial number at all.

Why you need your serial number

Your serial number is important for several reasons. If your computer needs warranty service or repair, the manufacturer or repair shop will ask for it to look up your coverage and service history. If your computer is stolen or lost, you can provide the serial number to police and to your insurance company as proof of ownership. Some schools and workplaces also track computers by serial number to manage their equipment inventory.

Keep your serial number written down or photographed and stored somewhere safe — separate from the computer itself. A good place is a document folder on your phone, a password manager, or a physical notebook kept at home. If you ever need to prove you own the machine, having this number readily available will make the process much faster.

What to do if you cannot find the serial number

If you have looked on the physical machine and checked system settings but still cannot find a serial number, the computer may be very old, heavily damaged, or custom-built. In that case, contact the manufacturer directly with proof of purchase — a receipt or invoice — and they can help you locate the information. Some older machines may have the serial number in different locations than modern ones.

If the sticker is worn away or unreadable, a repair technician can sometimes retrieve the serial number from the system firmware or from records if the computer was previously serviced. If you are trying to prove ownership for insurance or legal reasons and cannot find the serial number, your original purchase receipt or credit card statement showing the purchase may work instead.

Keeping your serial number safe

Once you have found your serial number, store it in at least two places. Take a photo of the sticker on your computer and save it to your phone or cloud storage. Write it down in a notebook or document file. If you use a password manager like Bitwarden or 1Password, you can store it there as well — these programs are designed to keep sensitive information find.

Do not post your serial number on social media or in public forums. While a serial number alone is not enough for someone to steal your computer, it is one piece of information that could be used along with other details. Treat it the same way you would treat a vehicle identification number on a car.

Frequently Asked Questions

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

No. The serial number identifies the physical machine itself. A product key or license key is used to set up software like Windows or Microsoft Office. They are completely different and serve different purposes. You need the serial number for hardware repairs or ownership proof, and the product key for software set up.

Can I find the serial number if I cannot turn on my computer?

Yes. If your computer will not power on, you can still find the serial number by looking at the physical stickers and labels on the case. The serial number is printed there regardless of whether the machine works. This is actually the most reliable way to find it if the computer is broken.

What if my serial number has letters and numbers mixed together?

That is normal. Serial numbers are alphanumeric, meaning they contain both letters and numbers. Write it down exactly as it appears, including uppercase and lowercase letters if they are different. When you provide it to a manufacturer or repair shop, they will tell you if you have made a mistake.

Do I need my serial number to sell my computer?

It is a good idea to have it available when you sell. A buyer may want to verify the serial number matches the machine and check the warranty status. You should also keep a record of the serial number for your own records in case the buyer later claims the computer was stolen or has outstanding debt attached to it.

Can someone use my serial number to access my computer remotely?

No. A serial number is just an identifier — it does not grant access to your files or allow remote connection. However, someone with your serial number could potentially contact the manufacturer and claim to be you if they also have other information like your email or purchase date. Keep your serial number private for this reason.