Removing network

I have a PC here, with an Ethernet card installed,and protocols for networking. I want it to run with only Dial-up-Networking, and remove the networking components I do not need. Does this mean removal of the Ethernet card, and removal also of Network components? Is this a simple process?

The main problem is that my client cannot configure the PC to automatically disconnect, because the connection to the ISP is going through a proxy, on account of the network having been installed on the PC.