win Vista dialup quite working

XPS Dell laptop running vista on July 11 win did a auto update and my dialUp
quit working Have talked to support for about 6hr 3 different days with as
many tech support people and still can not get it to work,tried
restore,update driver for the modem Dell No vista update drivers for my
modem Broadcom v.92 56k.Worked fine till the update.Tried uninstalling
updates,something got changed in my system that will not let modem work.On
error message said reason for disconnect was dtr drop code 32.I have talked
to my isp and all checked out ok on dialup from his end. My dialupworks fine
on my desktop and my other Hp laptop.Iam at a loss to why I can not get on
the internet with my dial up system.have turned off norton firewalls
etc.also done a virus scan .Any suggestion!!
Jim