i still facing problem with clients sometimes can't connect to network, when ipconfig /all, only show 'Windows IP configuration'. sometimes restart (will get blue screen background but only mouse cursor is active, have to off/on) or uninstall KAV 6.0.3.837 solved the problem. attached the getsystem info from one of the probem client.

Note : device driver is up to date

disable the Kaspersky Antivirus NDIS Filter on TCP/IP then only be able to access network & ipconfig /all list out the network details.
is it due to broadcom 440x 10/100 driver version, currently is using 4.25. the notebook is Dell Inspiron 700m