Can't get modem to uninstall under win xp

hi

i've been having a problem with my winmodem disconnecting ffrom my isp every 10 min. or so, and am in the process of getting a us robotics hardware modem as a replacement. while trying various fixes, like uninstalling & reinstalling the driver, and trying a different driver from conexant (it's an hcf modem using conexant chips), i've been unable to get the modem completely uninstalled. i go into the device manager, then the "properties" window for the modem, then into the "driver" tab. when i uninstall it, it no longer appears in the device list, but next time i start up the pc, it's back again.

how can i get rid of the old drivers completely, so as to have the cleanest possible setup for installing the new modem once it arrives?

thanks!

drew j.