I have a Problem with my LAN.

Hi,
I have Windows XP 2 service pack. Previously everything is fine with my LAN,now the problem is I am unable to get access of the shared drives and documents on the other systems in my work place, where LAN is active. In my system no Network regarding option is active and even I cant access the Firewall option in my control panel. View Work group computers, My network Places, every icon is not working, but I can access the internet. Also I am unable to Print through the Printers which are used through LAN.
Can I get a proper useful answer for my query please!
Thanks
Regards
Lavanyagangadhar.
