For system administrators or users who own a legitimate volume license key for Office 2013, here is the correct installation process, which some confuse with "pre-activated" setups when using internal KMS servers.
: If you have a physical key, you can enter it at office.com to link it to your account and download the setup file. Modern Alternatives Microsoft Office Professional 2013 -Pre-Activated- Download
: Provides the latest versions of Word, Excel, and PowerPoint with ongoing security updates. You can Compare Plans and Pricing on the official Microsoft site . For system administrators or users who own a
: A one-time purchase version for those who prefer not to have a subscription. You can Compare Plans and Pricing on the
It is important to evaluate if Office 2013 is even worth the trouble.
If you already own a legitimate license and need to reinstall it, here is the safest way to proceed: Official Download & Activation