Excel Key Activation < 2026 Release >

How to find product key for Microsoft Office already installed

There are two primary ways to activate Excel, depending on the licensing model you purchased.

| Problem | Solution | |--------|----------| | “Key already used” | Install on the same Microsoft account; otherwise, you may need a new key. | | “Key invalid” | Check for typos (don’t confuse 0/O or 5/S ). | | Activation server not reachable | Connect to internet, disable VPN, check date/time settings. | | Office shows unactivated after key entry | Run → cd C:\Program Files\Microsoft Office\Office16 → cscript ospp.vbs /act |

A Microsoft product key is a 25-character code used to verify that the software has not been used on more computers than the Microsoft Software License Terms allow. It typically looks like this: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX .