It is possible to make this work - but it can be non-trivial to explain. As a start - you could let us know what operating systems you are using.

Under some versions of windows (2K and ME at least) there is an 'Internet connection sharing' option that you can tick which will do most of the work for you. Finding this option can be a bind.

On this here W2K SP3 it is under Start|Settings|Network and Dial-up connections|"Your internet connection"|Right-Click, select properties|Select Sharing|The top tick box.

For this to work - you must have you computers properly networked - i.e. this will only work if your networking is otherwise set up properly.

I'm sorry - but I don't feel up to remotely diagnosing your network problems if the above doesn't help. You can still ask - someone may help.

Mark