This portion of the Basic Network Troubleshooting is probably the easiest and yet most easily misunderstood. Since anyone today building their first network will be using CAT5 or Twisted Pair cables, (believe me it is so much easier to use than Coaxial cable... ),  this discussion is about CAT5.

But, it need not be hard...  unless you make it hard.

A basic network, two PCs joined together to share the files on one and other, is composed of the following:

Cabling is usually the first thing to suspect:

Single cable setup
When you use only a single cable to connect two PCs, no hub or switch between them, the cable MUST be a cross-pin or Crossed-Over cable.  If you have a standard patch cable or straight through cable, it will not work.  To understand, go to our "Cabling Issues" page to read more:  Cabling Issues

Hub (or switch) Setup
If you have a hub and both PCs are connected to it with a separate cable, (this is seen more and more these days), the cables must be standard patch cables or Straight-though cables.

Network Cards:
Not the most sure-fire way to check the Network card, but if the small light on the back of your card is green, typically it is functioning properly.

Just like troubleshooting any I/O, (in/out), card, be sure the slot the card is in is functioning, you can always switch the card to another slot on the motherboard.  Be sure that the card has been assigned an IRQ by the Bios, preferably IRQ 10 or 11.  Can the card be bad right out of the box?  But, of course.  

A big issue here with any I/O card, but mostly with Network cards is to have the proper driver.  Windows will look at cards and load drivers it believes will work...  that does not mean they will work!  If you did not receive a disk with drivers when you bought the card, then download them from the manufacturer's web site.  If the card is too old to have drivers available or just an odd card with no drivers...  even buying a low-end card is better than fighting this nightmare.

You may get a bad Network Card right out of the box.  It does happen...  and if the card is bad, it is hard to troubleshoot.  That is why we should keep extra cards around, so we can switch out any card that does not seem to function properly.  You can pickup an extra card cheap Network card for under $16 dollars, (in the US), to switch out a card that does not seem to be functioning.  

The best way to insure that the hardware you are using is working is to BE CAREFUL with it during the installation.  Computer components fail most often because of mistreatment...  dropping them, banging them and so forth.  Yes, heat is a killer...  so is static electricity...  but, more components are damaged by mistreatment than anything else.

There is just not a lot more to tell you...  there is just too little that can go wrong with Network hardware.  So, be patient and if you have a problem, go slow switching out any perceived bad parts.