Custom-built PCs usually don't have serial numbers; depending on the situation, you may be able to create one or use the motherboard's serial number.

Need your motherboard’s serial number? Learn how to find it quickly and why it’s useful for support, upgrades, or warranty claims.

Quick methods for discovering your laptop's serial number for technical support, security, and more Reviewed by Jon Fisher You can quickly find your laptop's serial number by entering a simple ...