Figure 8: How to find out what COMs are in use
on your motherboard.
What if every IRQ and/or I/O range is already in use?
If you have lots of devices attached to your computer, this might
happen. A way to make room for your NIC is to disable any
users of your scarce IRQs or I/O resources that you dont
For example, if you have just one modem and no other
devices besides a mouse attached to your serial ports, you dont
need to use two of the four serial ports that most motherboards
allow. Your mouse will normally be using the first serial
port (COM1). You can check to make sure what COM your mouse
uses with the System Properties Device Manager. You modem
will usually use COM2, which you also can check on Device Manager.
If any other serial ports are in use, you will find them listed
in Device Manager. Figure 8 shows one way to check what
COM your modem uses.
If you are using less than four COMs, then you can safely
disable a serial port on your motherboard. To do this,
reboot your computer. At the very beginning, change your
BIOS by going into setup (usually by hitting the delete key.
Go to the Integrated Peripherals menu. Pick the last serial
port on the list that is shown using an IRQ and I/O resources.
Write these down, then disable that port.
Now go back to setting up your NIC -- and use the resources
that serial port you just killed used.
Another problem may be that you have a plug and play
NIC that wont plug and play. This may be the fault
of your motherboard. Go back into setup, and this time
go to the PNP/PCI Configuration menu. If this menu doesnt
exist, your motherboard probably doesnt support plug and
play. If it does exist, check to see whether plug and play
is enabled for your ISA and PCI slots. If not, set them
to plug and play.
If this doesnt fix your NIC, you have one more
option. Guess what, when Windows says your NIC is using
certain resources, it may be wrong! Sometimes a NIC wont
let Windows reset its resources, and instead of honestly telling
you this failed, shows you the resources you set in Device manager
instead of the real resources your NIC is using.
Here is where we learn about flash PROMs! Your
NIC may have a programmable memory chip (PROM). You can
use it to set the IRQ and/or I/O settings you need.
The nice thing about PROMs is that once you program
them, they stay that way forever, regardless of whether they
have power, unless you choose to reprogram them. However, often
Windows cant reprogram it for you.
So how do you program the PROM? Read any files
named README on your installation disk to find out how to do
this. It may ask you to reboot your computer into safe
mode to run the program to reprogram your NIC. If you have
a DOS boot disk, its often the easiest way to do that.
However, if you are new to computers, you probably dont
have DOS in you tool kit.
Heres how to get into safe mode. Shut your
computer down. Then before Windows begins to boot, hit
F8. This gives you a safe mode menu. Choose the DOS
mode your installation disks README file tells you to use,
and then run the installation program so you can choose an IRQ
and/or I/O resources that wont conflict with anything else.
If F8 doesnt work, its because someone
or some program decided to make that computer more secure by
turning off the boot keys feature. If you are running Boot
Magic, you must first have set it up so that Windows is the default
operating system (the one that boots if you do nothing).
If you arent running Boot Magic, your msdos.sys
program may have disabled boot keys. Instructions on how
to enable or disable the boot keys are in Section 1, Chapter
Cant ping your NIC from across the network?
After you get done saying bad words, ping the NIC that
didnt answer from inside your computer. If you are
still able to ping that NIC from inside its computer, there probably
is nothing wrong with your NICs. So your suspects for any
trouble are either you set up your IP addresses wrong, netmask
wrong, or there is a problem with the patch cord or the port
on the hub.
Check to make sure that you set up the TCP/IP settings
exactly as described above. Now is not a good time to improvise,
Next, check the cabling and hub. Here is where
any pretty lights on the NICs and hub come in handy. Each
NIC, if it is alive, should have a green light. Each port
on the hub that has a live NIC attached to it should also show
a light. You may also have extra lights that blink when
you send data (such as a ping) over your network; and for collisions
(too much data interfering with each other).
If your NIC has a light shining, and you can ping it
from inside your computer, it probably has nothing wrong with
it. Look at the port it connects to on the hub. Is
that light on? If it isnt, you should suspect the
First, make sure your patch cable is properly connected.
Take it off and attach it again. When the connector properly
seats, it makes a click. If you dont hear the click,
try pressing it in a little harder. If this doesnt
work, if another computer is working over the network, try trading
cables. If this fixes the problem, you probably have a
If this doesnt work, try attaching the cable to
a port on the hub that was attached to a computer that was able
to communicate over the network.
If none of your computers can ping any others, yet a
crossover cable connecting two NICs works, its time to
suspect the hub. This is where the crossover cable comes
in handy. Directly connect two computers with the crossover
cable. If they can talk to each other, you have something
wrong with the hub.
If setting up your Win98 network made you throw fits,
give up on calling yourself a hacker. Use this book for
a fly swatter or to shim up a table with uneven legs.
If you discovered that building a network was fun, you
are the kind of person who could become a systems administrator
or computer security expert. Hang on to your hat!
You will soon discover that Unix type operating systems are much
easier to network. Im betting that having succeeeded at
networking Windows computers, you will work out how to add other
operating systems on your own. And once you are able to
network many different operating systems, you will possess a
hacker laboratory that will open the doorway to the Uberhacking
skills of your dreams.
Back to building a Windows hacker