How to Find the Serial Number on Your PC: Every Method Explained

Every PC has a unique serial number — a string of letters and numbers assigned by the manufacturer that identifies your specific machine. You might need it to register a warranty, arrange a repair, contact support, or verify authenticity before buying a used device. The good news is there are several reliable ways to find it, and most take less than a minute.

What Is a PC Serial Number and Why Does It Matter?

A serial number (sometimes labeled S/N) is a manufacturer-assigned identifier unique to your individual unit. It's different from a model number, which identifies the product line — the serial number identifies your specific device within that line.

Common reasons you'll need it:

• Filing a warranty claim or repair request
• Registering your device with the manufacturer
• Reporting a stolen device to authorities
• Verifying a second-hand PC before purchase
• Matching replacement parts to your exact build

Method 1: Using the Command Prompt (Windows) 🖥️

This is the fastest method for most Windows users and works on laptops and desktops alike.

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

wmic bios get serialnumber 

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

If the result returns "To be filled by O.E.M.", it means the manufacturer didn't program the serial number into the firmware. This is more common with custom-built or white-label PCs. In that case, skip to the physical label method below.

Method 2: Using PowerShell

PowerShell offers the same result with a slightly different command — useful if Command Prompt isn't readily accessible.

1. Right-click the Start button and select Windows PowerShell
2. Type:

Get-WmiObject Win32_BIOS | Select-Object SerialNumber 

3. Press Enter — the serial number displays in the output

Both wmic and PowerShell pull this data from your system's BIOS/UEFI firmware, so the result is the same either way.

Method 3: Check the System Information Tool

For users who prefer a graphical interface:

1. Press Windows + R, type msinfo32, and press Enter
2. The System Information window opens
3. Look for "System SKU" or scroll down to find any listed serial references

Note: msinfo32 doesn't always display the serial number as prominently as the command-line methods. Its value is more in showing full system specs alongside any serial data your firmware exposes.

Method 4: Check the Physical Label

If software methods return blank results or you simply prefer a physical check, look for a sticker on the device itself. Typical locations vary by form factor:

The label usually shows the serial number alongside a barcode or QR code. On Dell machines it's often labeled Service Tag rather than Serial Number — functionally the same thing for support purposes.

Method 5: Check the Original Packaging or Documentation

If the device is relatively new or you kept the box, the serial number is printed on the retail packaging — typically on a label near the barcode. It's also commonly included in:

• The printed quick-start guide
• A warranty card inside the box
• Your purchase receipt or order confirmation email (for devices bought directly from a manufacturer or major retailer)

This is particularly useful if the device is damaged and physical labels are no longer readable. 📦

Method 6: BIOS/UEFI Settings

You can also find the serial number directly in your PC's firmware:

1. Restart your PC and press the BIOS key during startup (commonly Del, F2, F10, or Esc — varies by manufacturer)
2. Navigate to the System Information or Main tab
3. Look for Serial Number in the listed hardware info

This method is helpful when the OS won't boot but you still need the serial number — for example, before a clean Windows reinstall or when troubleshooting a major hardware failure.

When the Serial Number Comes Back Empty or Generic

Not every PC will return a clean serial number through software. This happens most often with:

• Custom-built PCs using a third-party case and consumer motherboard — the board has its own serial number, but there's no system-level serial assigned
• Rebranded or white-label hardware where OEM information was never filled in
• Very old hardware predating consistent firmware serial number storage

In these cases, your best option is the physical label on the motherboard (visible with the case open) or documentation from the system builder.

Factors That Affect Which Method Works for You

Not every method works equally well across all setups. The right approach depends on:

• Operating system version — older Windows versions may handle wmic differently; Windows 11 users may notice PowerShell is more accessible by default
• Manufacturer — some brands use proprietary tools (like Dell's SupportAssist or Lenovo's Vantage) that surface serial numbers through dedicated software dashboards
• PC type — branded laptops and pre-built desktops almost always have clean firmware serials; custom builds frequently don't
• Physical condition — worn labels or a damaged chassis make software methods the only option

The same serial number question surfaces very different answers depending on whether you're working with a brand-new OEM laptop, a decade-old desktop, or a self-assembled rig — and what you're actually trying to do with the information once you have it.