hai guys
i have a problem my pc (OS XP) is not able to connect to internet i have lan card installed on pc.both address local loop back and ip of lan card give reply when i ping both of these ,and in corner message appears "local area connection connected"but i am not able to access the internet and computer next to me access the internet .i connect to internet through local area network.plz help

The "local area connection" message could be refering to your loop-back adapter, not your LAN card. Can you ping your router? What happens when you open a command prompt and use the "IPConfig" command? Do the other systems on the network connect properly?

No i am not able to ping my router or default gateway and other system on the network connect properly when i ping ip of my own pc it gives reply .actally i want to know what is the best method to check lan card and there is some thing internal in the pc which stops internet from accessing.plz reply

I would try disabling the loop-back adapter first, because that might complicate things (and confuse them). once that's done go to your device manager under my computer or control panel and see if the drive is listed and marked as working. Then connect all cables and try to connect to your LAN.

I'm a little mixed up her, you're saying you can't ping your default gateway, is it showing a default gateway when you run IPCONFIG?

Generally prob.s in this area are firewall related. Tried to solve similar prob. some months ago. Although it IS supposed to work. After some considerable head scratchin and hair pullin I threw up my hands and did my internet bus. with the server with the modem installed.
General rule: no ping, hardware. ping no conn., software.

Right click "My Computer" select "properties", click the "hardware" tab, click the "Device Manager" button. Expand "network adapters" and find your ethernet card. Right click it and select "uninstall". Then immediately restart your computer.. When the machine reboots it will install your ethernet card completely fresh... This solves most connectivity problems. (as long as your router is set up for DHCP, which most are). Hope this helps.