Two computer connected to internet with one modem and switch

I have tow computers connected to a modem using a switch. Can i disable connection of one (computer ) without manually removing cable of that computer from switch.
and how can i check whether the other computer is successfully disabled or not?

You can disable the network by going to the properties of the My network places & the finding the active connection & then right click on it & then disable it by clicking on the disable button.

After disabling it try loading any page you need it will not connect to the internet

OR

Try connecting the internet it will ask you for connection error or to enable the network device.

This are the two basic way to check weather the connection is disabled or not...!

Actually you didnot understand my question . Let me explain it more clearly:

I have two computers A and B both connected to a single modem via a switch. Now, while operating on A can i disable internet connection of B .
And if i have done this, how can the person sitting at B come to know that A has disconnected his network (as B will still see his active network connection enabled but is not able to load any page)

Probably computer A can access the modem and then remove the IP of computer B from there, so then B cannot access internet because it is not listed in the modem settings. Now in similar way, if B access the modem, then it will come to know that it is not listed there and therefore it cannot access internet.

I am not sure if I am correct but I just thought this might work.