Pc's say a network cable is unplugged

Are you sure you got a compatible modem? They are not all alike.

3 ethernet cables 1 ADSL modem and 1 hub is needed to network computers together.
1. connect telephone cable to modem and switch it on. 2. one end of an ethernet cable is connected to the modem . consider this master ethernet cable. connect the other end of this to the master hub port. 3.now connect pc and any hub port with another ethernet cable(ec) say ec1 4. likewise ec2 to another pc .
try this out to get net in both pc's

This message " A network connection is unplugged" comes when the connection unavailable may be due to faulty connection. Chek that your router is rightly plugged and the sockets are dust-free. If problem persists, contact support.

1. Click Start => Settings => Network Connections
2. Right click on your LAN connection and click properties
3. Under General Tab, click the configure button to configure your Ethernet adapter
4. In the dialog box that appears, click the Advance Tab
5. Under Property, scroll down to SPEED and Duplex and set the property to 100Full

However, you can set it to its default value: Autonegotiation. It you have switch or hub that runs on 10mbps, it should run at 10 and not 100mbps

Most likely the connection inside your new gateway is bad - you should return it under warranty & get a new one.

Tony,  I was looking at the specs and found these lines :- Choices of 12 and 24 10BASE-T ports per hub 
1 100BASE-TX port (for connection to 100BASE-TX hubs) Which is saying that the user/pc ports are fixed 10Mps and there is one 100Mbps uplink port to connect two hubs together.
http://www.dlink-intl.com/Products/Hubs/DE1824.htm

Hi Ewan,

How is the modem/router connected to the switch?

Have you tried changing the patch cable that connects them together, or the port they are connected from?

When troubleshooting this type of issue, it is always best to check each layer of connectivity (1-Physical,2-Data Link, 3-Network Addressing, etc.) in order from bottom to top, due to each layer being dependent on the layers before it.

DNS is important but wont be available until you have a physical connection and a IP address.

If you can achieve a stable connection while the PC is connected directly to the modem/router, but not via the switch then work your way from one end of the link between the working component (in this case the modem/router) to the other (PC) - testing each part along the link.

If the switch is faulty after you have performed some testing, it is best to change it out and test with another switch (if avalible), before purchasing or sending the JFS524 away for repair (if still under warranty).

Let us know how you go with the testing.

ok, i think what you mean is this.  Crossover cable is for connecting 2 computers together without the need for a router.  also called pc-to-pc.  Straight cables need the use of a router or hub to connect 2 computers together.  Hope this helps, if not let me know more info.

Hi,

Check the following:

Hardware First: Is Vista confirming LAN connection onn that PC, or is it showing disconnected cable?

Is the connection properties showing at least 100Mbps?
Are the RJ45 terminals okay?
Is the driver for the network card recognized by Vista and loaded?

If that is fine, then check the following in the network properties:

1. The IP address you are using
2. The gateway address: it must be the same as the gateway address in the other PCs accessing internet. Run and check
3. The Subnet mask. Use 255.255.255.0
4. HAve you Setup the Nework using the Setup Wizard, including Access INTERNET THROUGH A HUB THROUGH ANOTHER COMPUTER ON MY NETWORK?

Check those things and let us know. Ask for help from your network administrator about correct IP addresses on that LAN

It's not generally possible to connect two computers directly via a network adapter.  You need a hub or router in between the two computers (you would connect a cable from each computer to the hub or router, and that equipment facilitates the connection between the two computers).  Alternatively, you would need a "crossover cable" to connect the two computers directly without a hub or router.