Compaq Presario 4706 – Modem upgrade

I have a Compaq presario 4706 originally WIN95 but now with WIN98SE installed, no problems as such except that I want to upgrade my Modem 336-VSC ver 1.14 to the V.90 standard as some ISP phone numbers cannot be accessed & it says that Modem cannot comuunicate with this number (V90) I would like to know from where I can downlaod the upgrade to this modem. Compaq site cannot help & they diverted me to the www.driverguide.com site where I could not find anything useful. Many thanks – Regards Khushroo Dholoo