I want to use a crossover Ethernet cable to connect two computers directly for file transfer between the two. I have several Ethernet cables, but not sure if they are crossover? How to tell a Ethernet cable is conventional or crossover? Thanks and regards!
Look at the ends of the cable. If the color order is identical, then it is a patch cable (or as you said "conventional"). If the color orders are different, then it is a crossover. Also, keep in mind that USUALLY (not all the time) crossover cables are red. Obviously they can come in any color though.
Below you can see the colors of the twisted pair wires inside of the RJ-45 connector. For more information on this, or if you would like to know about the TIA/EIA-568-A or the TIA/EIA-568-B standards, please refer to this wiki page.
Most modern Ethernet equipment will auto-negotiate and doesn't care whether the cable is cross-over or not.
Don't worry, most modern Ethernet cards support both modes and will automatically recognize type of the cable.