What Is a SLIC BIOS Entry?

By Dan Howard

Most new PCs come with a version of the Windows operating system on the hard drive. Although all files that you need in order to run the operating system are already present, you must activate the operating system's product license before it becomes functional. The information that your computer needs to activate a preinstalled Windows operating system is contained within system BIOS in a SLIC entry.


The term "SLIC" is short for software licensing description table. The SLIC table is a portion of system BIOS that is dedicated to containing operating system license activation information. SLIC tables are added to BIOS by large computer manufacturers to expedite the process of licensing operating system software on new computers. The process of activating an operating system with information preloaded into SLIC is called OEM activation.


Prior to activation, a BIOS SLIC table contains information that is referred to by Microsoft as the OEMTableID. The data includes a string of characters called a SLIC key that identifies the computer as eligible for OEM activation. Microsoft licenses a different public SLIC key to each computer manufacturer. A single computer manufacturer's SLIC key may vary based on the version of the operating system preloaded on the computer. Providing different SLIC keys for different manufacturers and different operating system versions ensures that a given Windows operating system product key can only unlock a single model of computer.

License Activation

When you first activate your operating system on a new computer with SLIC BIOS, you must type in a Microsoft Windows product key. Once you input the characters, your computer compares the specified product key with the SLIC public key that is contained in the SLIC table. If the two keys match, then your operating system license is activated and you can use your computer. If the product key does not match the key in the SLIC table, then activation fails.


There are a few reasons that SLIC activation may fail. The simplest fix if you encounter failure is to try typing in your product key again; the key is a long, arbitrary string of characters and just a single typo will prevent activation. If you're sure that you typed the product key correctly, then it is likely that your computer manufacturer loaded the wrong SLIC key into your computer's BIOS. You should contact the manufacturer and request updated BIOS service to fix the problem. Alternately, if you purchased a new computer from a third party source, then it is possible that you bought a counterfeit system. If this is the case, you can still activate Windows and use the computer by contacting Microsoft support and purchasing a license for the version of Windows that is loaded on the computer.