USB_ModeSwitch

I've got an unlocked Zoom Tri-Band USB modem that's installed on Windows 7 x64. When I plug the modem into the USB port, I see a mass storage device on the USB bus (no drive letter, not visible in Explorer) and the driver then launches the Zoom software suite. After a few seconds, the software UI indicates that the modem is connected to the (AT&T) network and I can then send/receive text messages, etc. using the Zoom software. If I then launch an app like Tera Term to try and connect to the modem so I can issue AT commands, I see three new serial ports:

COM18: HSPADataCard USB Device Management
COM19
COM20

Tera Term won't connect to COM18 at this point presumably because the serial port is locked by the Zoom software. I am able to connect to COM19 and/or COM20 and issue AT commands (I've tested this with several ATi# commands on both ports). However, as soon as I close the Zoom software, the modem seems to disconnect from the network. The COM ports don't disappear and I can still issue AT commands but most of them just return an error when the Zoom software is not running. Is it safe to assume that the driver and/or Zoom software suite is connecting/disconnecting the modem to the network? If so, would the functionality provided by USB_ModeSwitch enable/connect the modem without the need for the Zoom software? I'm writing my own software that needs to be able to send AT commands to/from this modem and it's not feasible/acceptable in this scenario to have the Zoom software always running.

For what it's worth, the modem I'm using can be found at http://www.zoomtel.com/products/4598.html. Thanks very much for any advice you can give me!

I'm not sure it's the driver that starts up the software.

Usually, there is a resident autostart task that in turn watches the driver. If you disable that ("msconfig" or registry RUN key), the device should be able to start up without being tweaked.

Hi Josh. You're absolutely right about the resident process (MCtlSuc.exe) that kicks off the Zoom software when the modem is inserted. I killed that process and things seem to be working as expected now. Thanks very much for your help!

Just keeping a Shift key pressed while you insert the modem might also work - if there was no program you had to install when using the modem for the first time.