Hey Jim: I've also been frustrated by this issue but may have stumbled on how Vista can handle the installation.

AllTel will hide behind the "we haven't gotten the proper driver from Microsoft" excuse.

The way I got mine to work was, modify the provided .inf file with the suggestions provided on the Microsoft link provided above, which boils down to ensuring that you add the following line "include=mdmcpq.inf" under the following captions [Modem1.NT]; [Modem1.NT.Services] and [Modem1.NT.HW]

Start the modem and plug into the computer, assuming this is not the first time you've attempted this, the USB new device discovery won't show up, instead, the modem will show and an improperly configured modem under the name "Prototype" in the Device Manager, right click and click on update driver, DO NOT let Windows do it automatically, instead, point the installation to the path where the modified .inf file is.

The installation should complete succesfully. I have tested the modem couple of times and is working fine.

Good luck...

Big Al

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