Hi everyone, I having a very difficult time understanding why my laptop can't connect online. I have dsl connection connected to a router then to a switch. On the LAN I have two other desktops with 10/100 network adapters however the laptop's built-in network adapter is 100 mbps network adapter, so I am wonder if that is the problem? every network adapter on a LAN must be 10/100 or 10 or 100 but can mix. is this correct?

check to see if your switch is 10/100 autosensing. Also, check to see if your laptop can ping the other machines and vice versa.

Yup, the switch is 10/100, but I am unable to ping other computers on the LAN. The laptop seems to be unable to catch the ip address distributed by the router with the dhcp. Wierd.

Is it possible that there are network adapters on the LAN that are 10/100 and 100. the laptop has a 100 network adapter and the desktops have 10/100 network adapters.

hmm... It shouldn't matter that you have adapters running at different speeds. Check your device manager to make sure the adapter is functioning properly. If it is, make sure your adapter is accepting DHCP, then try renewing the IP address on your interface: At the command prompt type: ipconfig /release then ipconfig /renew

You say you are going through a router and a switch. Many basic routers and switches are only 10 Meg and not switcheable. If this is the case with yours, you will not be able to communicate through those devices with a straight 100 Meg card. To verify this you could use a cross over between the notebook and a workstation, if it works this may be your situation.