Spreadtrum chipsets are notorious for randomly dropping IMEI after a factory reset or OTA update. V41 fixes this reliably. In my testing, 19 out of 20 phones showed proper IMEI and network registration immediately after writing.

Because v41 is lightweight (uses only 15MB of RAM), you can open multiple instances. Connect four different Spreadtrum phones to a USB hub, run four v41 windows, and write IMEIs in parallel. This was impossible in v32 due to COM port locking.

Changing or altering IMEI numbers can have legal consequences in some jurisdictions. It's essential to use these tools for legitimate purposes only.