I'm not sure what you mean by availability (because you mention a screw driver).
- If your computer has a (Ethernet) port which you can plug a network cable into, then you have a network card present.
- If you want to know if the network card is picked up and/or activated by RH 5.2 use one of the following commands:
lspci | grep -i eth
dmesg | grep -i eth
Hope this helps.