My bluetooth usb dongle working with Vista for Mobilink GPRS connectivity. You have to insert a special modem initialising string.
User name mobilink
Password mobilink
Dial-up number *99#
Modem Configuration
Try repairing modem settings: Start - Control panel -Phone and Modem Properties - Modems - choose the right terminal (e.g. PC Card Option Globetrotter) - Properties - Advanced - Extra initialization commands:
For Indigo Customers
AT+CGDCONT=1,"IP","connect.mobilinkworld.com"
For Jazz Customers
AT+CGDCONT=1,"IP","jazzconnect.mobilinkworld.com"
Check whether the phone number in dial-up networking is:*99#