What is oem key

Last updated: April 1, 2026

Quick Answer: An OEM key (Original Equipment Manufacturer key) is a Windows product license pre-installed by computer manufacturers on new computers. It is significantly cheaper than retail licenses but cannot be transferred to different hardware and remains tied to the original computer.

Key Facts

Understanding OEM Keys

An OEM key is a Windows product license sold exclusively to original equipment manufacturers (OEMs) like Dell, HP, Lenovo, and ASUS for pre-installation on new computers. These keys are provided at a significant discount compared to retail licenses, making them attractive to manufacturers and consumers buying pre-built systems.

Key Characteristics

OEM licenses have several important limitations compared to retail licenses:

OEM vs. Retail Keys

The main difference between OEM and retail keys is transferability and support. Retail keys can be transferred to new hardware and include Microsoft support, while OEM keys are permanently bound to original hardware with limited support. Organizations frequently purchase retail licenses for flexibility, while consumers buying pre-built computers typically receive OEM licenses.

Purchasing OEM Keys

While OEM keys are primarily sold to manufacturers in bulk, they can be purchased individually through third-party resellers and online marketplaces. However, purchasing separate OEM keys is controversial, as it technically violates licensing agreements since OEM licenses should only be sold as part of new computer systems. Many vendors selling standalone OEM keys do so in a legal gray area.

When to Use OEM Keys

OEM licenses are ideal for consumers building new computers or purchasing pre-built systems who don't plan to upgrade components frequently. They provide significant savings and work perfectly for permanent installations. However, retail licenses are better for users who upgrade hardware regularly, need transfer flexibility, or require Microsoft technical support.

Related Questions

Can I transfer an OEM Windows key to a new computer?

No, OEM keys are permanently tied to the original hardware and cannot be transferred. If you build a new computer or replace key components like the motherboard, you will need a new license. Retail keys can be transferred after deactivation on the old system.

What is the difference between OEM and retail Windows licenses?

OEM keys are permanently bound to original hardware, offer no transfer rights, and include limited support, but cost significantly less. Retail keys are transferable, include Microsoft support, can be upgraded, but cost substantially more.

Is buying OEM keys separately legal?

Legally, OEM licenses should only be sold with new computer systems. Purchasing standalone OEM keys from third-party sellers exists in a gray legal area, and Microsoft may refuse activation if they determine the license wasn't legitimately obtained with original hardware.

Sources

  1. Wikipedia - Windows Product Key CC-BY-SA-4.0
  2. Microsoft - Windows Product Key Support proprietary