IBM Thinkpad T60

Hello, i have a problem with an IBM thinkpad t60, my rj45 cable is connected and all lights are flashing, but it keeps saying that the network cable is unplugged. tried it in two different environment and same issue. it has windows 2000 installed with an intelproset network adapter.
it used to work fine but stopped working after i’ve installed a VPN software on it.

Can anyone tell me what is going on?