Recognize the Expansion Slots

Once you have opened the computer, the next step is to recognize the appropriate expansion slots and identify an available one.    The steps involved in this part of the process are as follows:

1. Locate the expansion slots  
-- The slots are located on the motherboard where the expansion ports open out of the case.
Do NOT confuse the expansion slots with memory slots. 

2. Ascertain the type of network card you to install 
- PCI:  Will fit into the short, white expansion slots (see graphic below). 
- The current standard in internal network cards.  You will usually see these.

- ISA:  Will fit into the longer black expansion slots (see graphic below). 
- You will rarely see this as this technology has been abandoned by most vendors. 
- You may see it in older computers only.

3. Choose the appropriate available slot  
Normally, it should not matter which available slot you choose for the card, as long as you're putting the right type of card into the right type of slot. 
- Sometimes, however, if the card is installed into a slot, but does not work, it is worth attempting to use another slot, if available.