>> Yes, there is a loopback test which the manufacturers diagnostic
>> software can run. However this does not guarantee that it is
>> capable of sending a signal down an ethernet wire. When it
>> comes to it the only practical way to test an ethernet card is
>> to try it out.
>> BTW, if you're using a single ethernet card to an ethernet cable
>> modem there's a good chance you'll need to use a crossover
>Can you or someone else please explain what you mean by this: "if
>you're using a single ethernet card to an ethernet cable modem
>there's a good chance you'll need to use a crossover cable".
A regular ethernet cable is just one you would buy everyday. Some
cable modems require a cross over cable. In this case two of the wires
are crossed over in the ethernet cable in the same way as you would
need if you were plugging a PC ethernet straight into the back of
another PC's ethernet. You just go to a shop and ask for an ethernet
cross over cable. Thats it, nothing too special. Some modems (NTL
provided one for a start) auto sense the cable type and internally
provide the cross over function so you can just use a regular cable.
It works most of the time, but for some reason my 3com hub confuses it
and I have to set the uplink button on the hub. 
To sum it up. Plug in the modem. If its NTLWorld you'll get a lead
with it and it will work fine. If its any other and it doen't work and
you suspect the cross over, go to a shop and say "Can I have an
ethernet cross over cable", They'll say "Will 2 meters do you mate"
and take a few sobs off you for your nice new cable. It may even be in
a fetching shade of yellow. If it then works you can then tell people
that "My modem needs a cross over, I know all about cross over
Have a search on google.com for ethernet cross over cables and you
will probably get a diagram of the two wires that are wired back to
front to provide the cross over bit.
 I'm using a hub becuase a) it was free b) thats much cheaper than
buying a load of extra long ethernet cables c) I'm only using on PC
into the modem at a time anyway, d) oh did I mention it was free.
This post does not reflect the opinions of all saggy cloth
cats be they a bit loose at the seams or not
GSX600F - Matilda the (now) two eared teapot, complete with
white gaffer tape, though no rectal chainsaw