How stop wireless laptop hijacking the internet connection?

["G.Landon" <g.landon@xxxxxxxxxx>]

Hi guys.

The new NetGear router installed fairly easily on the PC (connected via 
ethernet) and I was then using the internet immediately!

Then the wireless laptop was switched on and it indicated it had found the 
wireless connection automatically (without me having done anything) and I 
was able to access the internet immediately - although in "unsecure mode" 
(if that means anything to you - it doesn't to me).

However, returning then to the PC it's internet connection had been lost! 
It was AS IF the wireless laptop had hijacked it.

Anyway, the NetGear installation disc was then placed inside the laptop for 
the first time and the Installation Wizard on it began.  After a very few 
keystrokes the wizard said it had done the job.  I then noticed that the PC 
was connected again to the internet.  So something good appeared to have 
been done!

However, this morning the wireless laptop was booted up first.  It connected 
to the internet.  Later the PC was switched on . . . and again it had no 
internet connection.  The "Repair" function won't restore it.

What needs to be done so that both machines completely share the internet 
and one doesn't hijack it from the other?

Thanks a lot.