Your serial number is printed on a sticker or shown in your system settings
The serial number of your computer is a unique identifier assigned by the manufacturer. You'll find it either on a physical sticker attached to your device or in your operating system's settings. The location depends on whether you have a Windows PC, Mac, or Linux machine, and whether it's a laptop or desktop.
Most people need their serial number for warranty claims, tech support, or when selling or donating a computer. It's different from your product key (which unlocks Windows) or your MAC address (which identifies your device on a network). Knowing where to look saves you time when a manufacturer or repair shop asks for it.
Key Takeaways
- Laptops usually have a serial number sticker on the bottom or inside the battery compartment; desktops have one on the back or side panel.
- In Windows, you can find your serial number by opening System Information or running a command in PowerShell without opening any physical panel.
- Mac users can locate the serial number in About This Mac under the Apple menu, or on the bottom of the device for older models.
- Linux systems store serial number information in system files that you can read through the terminal if the manufacturer included it.
- Taking a photo of the sticker or writing down the number in a safe place prevents you from having to search again later.
Finding the serial number on the physical device
The easiest way to find your serial number is to look for a sticker on your computer itself. On laptops, check the bottom of the device first—flip it over and look for a label with small text. The serial number is usually listed as "SN," "Serial Number," or "S/N" followed by a string of letters and numbers.
If your laptop has a removable battery, the serial number may also be printed inside the battery compartment. On desktop computers, check the back panel and the sides. Some manufacturers place it on the front bezel or inside the case near the power supply. For all-in-one desktops like iMacs, look on the back of the screen or on the stand.
Write down the number or take a clear photo of the sticker. Serial numbers can fade over time, especially on older machines, so having a backup copy is useful for warranty claims or if you need to reference it later.
Checking Windows System Information
Windows stores your computer's serial number in System Information, which you can open without taking apart your device. Right-click the Start button, select "System," and scroll down to find "Device name" and other basic information. This screen shows your computer's name and Windows version, but not always the full serial number.
For the actual manufacturer serial number, open the Run dialog by pressing Windows key + R, type msinfo32, and press Enter. System Information will open. Look for "System SKU" or scroll down to find "Serial Number"—the exact label depends on your manufacturer. Some computers list it as "System Serial Number" or "Product Serial Number."
If System Information doesn't show the serial number, you can try PowerShell. Right-click the Start button, select "Windows PowerShell (Admin)," and type Get-WmiObject Win32_BIOS | Select-Object SerialNumber. Press Enter, and the serial number will appear on the next line. This method works on most Windows machines and doesn't require you to open the case.
Locating the serial number on a 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 model, processor, memory, and other details. Look for "Serial Number" in the list—it's usually near the top. You can click the serial number to copy it to your clipboard.
Older Mac laptops and desktops also have a serial number printed on a sticker. For MacBooks, check the bottom of the device. For iMacs and Mac minis, look on the back or bottom. The sticker method is useful if your Mac won't turn on or if you need the number before booting the system.
If you're selling or recycling a Mac, Apple recommends noting the serial number before you erase the device. You can also find it on your original purchase receipt or in your Apple ID account under "Devices" if you registered the computer when you bought it.
Finding the serial number on Linux systems
Linux machines don't always display the serial number in a graphical menu the way Windows and Mac do. The process depends on whether your Linux computer is a laptop, desktop, or server, and whether the manufacturer included serial number data in the system files.
Open a terminal and type sudo dmidecode -s system-serial-number and press Enter. You may be asked for your password. If the command returns a serial number, that's your system serial number. If it returns nothing or an error, your Linux installation may not have access to that data, and you'll need to check the physical sticker on your device instead.
Another option is to type cat /sys/class/dmi/id/product_serial in the terminal. This reads the serial number from the system's firmware if it's available. Not all Linux systems have this information stored in the same way, so one method may work while the other doesn't.
Serial numbers for laptops versus desktops
Laptop serial numbers are usually easier to find because manufacturers print them on the bottom or inside the battery compartment. Since laptops are portable and more likely to be sold or serviced, the sticker is placed where it's visible without opening the case.
Desktop serial numbers are often on the back panel or side of the tower, where they're less visible during normal use. All-in-one desktops like iMacs or Dell XPS All-in-One machines may have the sticker on the back of the screen or on the stand. If you can't find it on the outside, check inside the case near the motherboard or power supply—some manufacturers print it there as well.
For both types, the system settings method (System Information on Windows, About This Mac on macOS) is faster than searching for a physical sticker, especially if the sticker has faded or been removed.
What to do if you can't find your serial number
If the sticker is missing or unreadable and your system won't boot, contact the manufacturer's support team with your proof of purchase. They can often look up your serial number using your name, email, or the order number from when you bought the computer. Have your receipt or order confirmation ready.
If your computer is under warranty and you need the serial number for a claim, the manufacturer may accept other forms of identification like your proof of purchase or the device's MAC address (which you can find in network settings). Explain that the sticker is damaged or missing, and ask what alternative information they need.
For used computers you've purchased, ask the previous owner if they have the serial number written down or photographed. If the device is a business computer, the IT department may have the serial number in their inventory system.
Frequently Asked Questions
Is the serial number the same as the product key?
No. The serial number is a unique identifier for your physical device, assigned by the manufacturer. The product key (on Windows) is a code that unlocks your operating system software. You need both for a complete warranty claim, but they are different numbers found in different places.
Can I find my serial number if my computer won't turn on?
Yes. Check the physical sticker on the bottom, back, or inside the battery compartment. You don't need the computer to be powered on to read a sticker. If the sticker is missing or unreadable, contact the manufacturer with your proof of purchase.
What's the difference between serial number and MAC address?
The serial number identifies your specific device. The MAC address identifies your device on a network and changes if you replace the network card. For warranty or support, always use the serial number. You'll find the MAC address in network settings, not on a sticker.
Do I need my serial number to sell my computer?
It's helpful to include it in your listing so the buyer can verify the device's history and check for recalls. Some buyers also want it to confirm the computer hasn't been reported stolen. Write it down or take a photo before you erase the device.
Where is the serial number on a gaming laptop?
Gaming laptops follow the same rules as standard laptops. Check the bottom panel first, then the inside of the battery compartment if it's removable. If you can't find a sticker, use System Information on Windows or About This Mac to locate it in your system settings.