Sounds like WinDoze has installed what it thinks the most appropriate driver for your modem as it recognised the chipset.
But, like with graphics adapters, the chipset is not the modem . . .
Your dealer should have given you a driver disc with the modem (floppy or CD) and this will have the best driver for the implimentation of the chipset that the manufacturer of your modem built - this is what you should, preferably, be using. Sometimes dealers buy a whole case of cards, modems etc, and the manufacturer gives them only one driver disc (I know as the company I work for sometimes has this problem)
So chase the dealer who sold you the system for the origianl driver, or a copy of it. If all else fails try the manufacturer's web site, or
www.thedriversite.com, and get the right software.
Uninstall the modem (sortware) and next time "Plug&Pray" detects new hardware, click on "have disc" and load the driver from that - not the "generic" driver for the chipset
Have fun!!
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What goes around . . .
. . often lands better!