→ Open Device Manager. Do you see "Modem" or "Ports (COM & LPT)"? If not, install the correct USB drivers (e.g., Huawei Data Card Driver, Sierra Wireless Legato).
Even offline installers contained a hardcoded expiry date. After a certain date (e.g., December 31, 2021), the software would refuse to unlock any modem, displaying "Trial period expired." gsm multihub modem unlocker fixed
The primary function of this tool is to calculate or inject unlock codes into GSM modems to allow them to accept SIM cards from any service provider. → Open Device Manager