Typically, Office Tab requires a purchased license key or a trial reset tool. A "pre-activated" version means the software has been modified to bypass the online activation server or has a valid enterprise license key embedded. While convenient for testing or personal use, pre-activated software exists in a legal gray area. Organizations should always purchase volume licenses directly from the developer (ExtendOffice) for compliance.
While this article provides information for educational and troubleshooting purposes, you should consider the following: Office Tab Enterprise 15.1.0.149 Pre-Activated 64 Bit