Is there any software capable of governing the bandwidth on my networked computers. I have 3 computers running off a single 10mb connection. 2 of which I want to limit the bandwidth down to 2Mb each so I can conserve bandwidth for the main computer. I have installed netlimiter on each of the computers which works fine on two of the computers but refuses flatly to run on the third (which is one of the computers I want to limit.) I have checked router settings just in case there was any settings there but to no avial so it will have to be a software based solution.

Thanks.

Try this link for several options:
http://www.brothersoft.com/downloads/bandwidth.html

What type of connection do you have and what type of router or hub\switch are you using.
One way to control all of your computers is to install a Proxy server and router all traffic through it. With a proxy server you will have total control fro bandwidth to content filtering and logging of usage.