You open the Huawei firmware updater ( Firmware_Writer_E1750.exe ). It says "Waiting for device on COM5..." You point it to the original firmware .dload file. The flash begins. After 8 minutes, the modem reboots. Device Manager now shows "Huawei Mobile Broadband Network Adapter." You have saved a $40 device using a 50KB driver.
The Huawei USB COM 1.0 driver is a specialized interface driver that allows a Windows PC to communicate with a Huawei or Honor device when it is in (or "Emergency Download Mode"). huawei usb com 1.0 driver.zip