One MB is usually enough. Video cards can be replaced but not repaired. The ethernet card physically connects your computer to the network. Ethernet cards are available through the Helpdesk or can be ordered with the computer system. They can be replaced but not repaired.
SIZE is often the main consideration when selecting a hard drive.
A single digital piece of information, generally represented by the numeral 0 or 1. A bit is the smallest piece of information that a computer deals with. Byte is equal to eight bits. As a frame of reference, two issues of Scientific American magazine would total about one megabyte of information. As of today, a drive is still considered BIG at one gigabyte in size, but probably not for long.