cannot install the adsl modem drivers

ok probably a long shot the ISP could noit even sort this problem out, i have a BT Voyager modem adsl everything installs well except the drivers this is the message i get "CANNOT INSTALL THE HARDWARE THE SYSTEM CANNOT FIND THE FILE SPECIFIED" now we have tryed every avenue the support line could do personaly i think thre is a way, or a conflict. so the problem again is the setup wizard that helps me install the drivers from the disk provided by the ISP gets so far then that message is there a way of checking if my USB ports are fine i think they are, what my ISP is saying to me is buy my own modem adsl and install the drivers for that and ring them back for the sevice, when by rights the modem they provided should be fine, they tell me for some weird reason the drivers are there they just won't install any help would be appreciated even a long shot answer as i badly need my adsl up and running thank you in advance