Internet access through GPRS Mobile Phone

Hello,
i am using Nokia 3500 C handset with BSNL GPRS, whenever i access it o my mobile phone it works perfectly. but when i try to access it on my laptop (Dell Inspiron 15 with windows 7 Home Edition) it do not work. On Nokia PC Suit One touch Access windows i got message “ One Touch Access Failed to establish a network Connection. Please cheak the connection settings.” & on my cell phone i got message “ Subscribe to Packet Data First”.
How can i able to access internet through my GPRS enabled handset,
Please suggest.

Chinu
Chinmaya_nandi@yahoo.com