I don't know if there are any "latest drivers".
Do you not have the ntl CD still? That has the USB drivers on it.
If you need to download the USB drivers, they can be found here:
http://homepage.ntlworld.com/myron.s/BB-DeviceDrivers/ (the ntl home modems are Ambits).
If you have a network card in your PC (& if not, you can buy them for less than a tenner), you could instead use ethernet to connect to the modem, rather than USB. No need for any drivers for the modem, & you would have a more stable & less resource hungry connection.