Check the sticker or label on the PC case, back panel, or bottom of a laptop
Open Command Prompt and run `wmic bios get serialnumber`
Open PowerShell and run `Get-CimInstance Win32_BIOS | Select-Object SerialNumber`
Open System Information and look for the BIOS Serial Number
Check the BIOS or UEFI setup screen
Check the original box, receipt, or warranty documents
Use the manufacturer’s support app or website
Check the device settings or about page if it is a prebuilt PC or laptop