How to Check Your PC Serial Number (Every Method That Works)

Your PC's serial number is a unique identifier assigned during manufacturing. It's not the same as a model number — it's specific to your individual unit. You'll need it for warranty claims, insurance documentation, IT asset tracking, or if a repair shop asks for proof of ownership. Fortunately, there are several reliable ways to find it, and most don't require opening the case.

Why the Serial Number Matters

The serial number (sometimes labeled S/N or Service Tag depending on the manufacturer) ties your device to its production record. Manufacturers use it to verify warranty status, identify hardware revisions, and track replacements. It's different from the model number, which applies to an entire product line, and different from the Windows product key, which is tied to your OS license.

Method 1: Check the Physical Label 🔍

The simplest starting point is the machine itself. Common locations include:

• Laptops: Underneath the chassis, near the battery compartment, or inside the battery bay
• Desktops: Side panel, rear panel, or top of the tower
• All-in-ones: Back of the display unit

The label typically shows a barcode alongside the serial number string. On some machines — particularly business-grade Dell, HP, and Lenovo units — you'll see it called a Service Tag rather than a serial number. Functionally, it serves the same purpose.

If the label is worn, scratched, or missing, the software methods below will get you there without any physical inspection.

Method 2: Use the Command Prompt (Windows)

This is the fastest software method and works on virtually every version of Windows from 7 onward.

Steps:

1. Press Windows + R, type cmd, and hit Enter
2. In the Command Prompt window, type:

wmic bios get serialnumber 

3. Press Enter — the serial number appears on the next line

If the output returns SerialNumber followed by blank space or a string of zeros, it usually means the manufacturer didn't burn a serial number into the BIOS/UEFI firmware — which occasionally happens with custom-built or white-label machines.

Method 3: Use PowerShell

PowerShell offers a slightly different path to the same BIOS data:

Get-WmiObject -Class Win32_BIOS | Select-Object SerialNumber 

Run this by opening PowerShell (search for it in the Start menu), pasting the command, and pressing Enter. The result should match what wmic returns.

Method 4: Check System Information

Windows includes a built-in tool called System Information that surfaces hardware details in a readable format.

1. Press Windows + R, type msinfo32, and press Enter
2. In the left panel, make sure System Summary is selected
3. Look for System Serial Number in the right-hand list

This method is useful if you prefer a GUI over the command line, and it also surfaces other useful identifiers like the BIOS version and System SKU.

Method 5: Check the UEFI/BIOS Directly

If Windows won't boot or you need to verify the serial number at the firmware level:

1. Restart your PC and enter the BIOS/UEFI (typically by pressing Del, F2, F10, or Esc during startup — the exact key varies by manufacturer)
2. Look for a System Information or Main tab
3. The serial number is usually listed here alongside the model and firmware version

This method bypasses the operating system entirely, so it's useful for troubleshooting scenarios where the OS is inaccessible.

Method 6: Check the Original Packaging or Documentation

If the machine is relatively new, the serial number is often printed on:

• The retail box (usually near the barcode)
• The invoice or receipt from the retailer
• The manufacturer's warranty registration email

For laptops bought through a business or IT department, the serial number may already be on file in an asset management system.

Comparing the Methods at a Glance

When the Serial Number Doesn't Show Up 🖥️

Some scenarios where the standard methods return empty or placeholder results:

• Custom-built PCs — Individual components like the motherboard have their own serial numbers, but there's no system-level serial number assigned
• Virtualized environments — VMs may return auto-generated or blank values
• Modified firmware — BIOS reflashing or certain OEM configurations can overwrite serial data
• Older machines — Pre-UEFI systems sometimes don't store this information in a software-accessible location

In these cases, the physical label (if present) or the original purchase documentation becomes the only reliable source.

Custom Builds vs. Pre-Built Systems

This distinction matters when deciding which method to rely on. Pre-built systems from major manufacturers — Dell, HP, Lenovo, ASUS, Acer, Microsoft Surface — almost always have the serial number stored in firmware and readable via wmic or msinfo32. Custom-built machines assembled from individual parts typically don't have a system-level serial number at all; instead, each component (motherboard, GPU, storage drive) carries its own identifier, accessible through separate tools like HWiNFO or CPU-Z.

The method that works for you depends on what kind of machine you're working with, how it was configured, and whether the firmware was set up to expose that data in the first place — which is something only your specific setup can answer.