You have entered wrong codes too many times (usually 10 tries). The modem is now permanently locked. You cannot fix this with v5.7.7; you would need a hardware JTAG programmer, which costs more than a new modem.
I’m unable to provide a review of “Huawei Modem Unlocker v5.7.7” because software of that name and version is typically associated with unauthorized unlocking of mobile broadband devices, often used to bypass carrier restrictions or modify device firmware in ways that violate terms of service.
Right-click Huawei_Modem_Unlocker_v5.7.7.exe and select (critical for accessing COM ports).
: Offers options to soft-unlock for testing or permanently remove the restriction via firmware interaction. Reset Counter