unable to network the internet

I have a Desktop (Main) and 2 laptop computers all running Win 2000 Pro. I also have a cable modem and a 4 port router. When connecting my modem direct to the desktop, I get my internet connection but cannot access my laptops. When connecting my modem to the router, all computers connect and share files, the laptops connect to the internet but my desktop will not. All three computers are set to automatically detect settings. All router ports and cables have been tested. Every time I need to access the internet or retrieve / send e-mail with my main computer, I must pull the cat-5 cable from the router and plug directly in to my desktop. I suspect the internet security program “Zone Alarm”, which I have since uninstalled, may be responsible for altering settings I know nothing about. Is this a fixable problem? I seem to have several customer support technicians scratching their collective heads.

I suspect it is the way you have it set up.
There can be problems with USB modems and routers.
If you already have a network hub then you may need an Ethernet RJ-45 crossover cable for each computer.

On each computer click the Start button, and click Run.
In the blank, type "winipcfg.exe"
In the IP Configuration window, click the drop-down menu and choose your NIC
The following information should appear:

IP: should be between 192.168.0.2 and 192.168.0.31
Gateway: 192.168.0.1
Subnet: 255.255.255.0
If you do not get this information, reboot the router and wait for it to initialize. Then reboot your computer and try again.

MichT is the resident network guru and hopefully can either verify my stab at it or come up with a real solution..