The easiest serial-number source is often the computer’s original label or manufacturer support tool. If the label is missing, Windows can read a value supplied by the firmware, but that value can be blank or generic on some computers.
Start with the physical records
- Check the underside, back or other manufacturer-specified label location.
- Look for “Serial”, “S/N” or a service identifier, separately from the model number.
- Check the original packaging and purchase records.
- Use the manufacturer’s genuine support utility or firmware information page.
Lenovo’s identification guidance gives examples; other manufacturers use different labels and terms.
Read the firmware value with PowerShell
Open Windows PowerShell or an appropriate PowerShell session in Terminal and run this read-only command:
Get-CimInstance -ClassName Win32_BIOS | Select-Object -ExpandProperty SerialNumberMicrosoft documents the Win32_BIOS class and SerialNumber property. This reads information the system supplies; it does not generate a new manufacturer serial number.
Old instructions using wmic may fail on newer Windows installations because that command-line utility is deprecated and may be absent. Get-WmiObject also differs from current PowerShell’s CIM approach. Do not install a random utility simply to reproduce an old command.
Can you find the PC serial number from Command Prompt?
On Windows with Windows PowerShell available, you can run the same firmware check from CMD by asking PowerShell to execute it:
powershell -NoProfile -Command "(Get-CimInstance -ClassName Win32_BIOS).SerialNumber"This reads the firmware’s serial-number value; it does not change the machine. Microsoft’s PowerShell command-line reference explains the invocation. If the value is blank or generic, use the label or manufacturer’s records instead.
Understand an unexpected result
| Result | Meaning |
|---|---|
| A plausible manufacturer identifier | Compare it with labels or official support records. |
| Blank or a generic placeholder | The firmware may not supply the expected identifier. |
| A custom-built desktop | There may be no single whole-PC serial; components have their own records. |
| Device ID or Windows product ID | These are not necessarily the manufacturer serial. |
Use the serial privately
Give the serial number to the manufacturer through its official support service when needed. Don’t post the full number or licence details in public screenshots. Keep the model and purchase details too: the serial number alone may not tell you whether the warranty covers your repair.
See which laptop labels are useful to keep before removing an identifying sticker.
Reviewed October 12, 2026, using the sources linked above.