This makes any disks or CDs that you insert into these drives a possible source of virus infection. The network adapter card is most likely your computer network and modem card connected to the local Intranet and the Internet. Virus enters through the network card most likely disguised in the form of attachments in e-mails. Not only that, but certain websites that we visit on the Internet may also contain harmful programming codes that might transfer virus or virus-like codes into our system. These viruses come alive with the simple opening of a program. The virus then installs itself into the computer's memory. The virus, now begins to spread, which is where things get pretty nasty. After entering the computer memory, a virus often immediately sets out to multiply and spread duplicate copies of itself across the main data storage device. It does this by copying itself into as many files it can find on the disk drive. Later when users transfer or copy these files to their friends, the virus gains entry into an increasing number of systems. If the virus has found it's way to this level of the user's computer, the user runs a high risk of permanent damage to data and hardware. The only good thing here is that the majority of the time, this only happens only to two kinds of computer users, those who do not employ any kind of anti-virus measures and those who do have good anti-virus programs installed and running but did not bother updating their software with the latest virus data files. If a virus were to just spread itself, users might not have much to worry about but many viruses contain what is called a payload. This is the destructive sequence that is activated on a certain trigger, which can be the arrival of a particular date or an action done by the user. The effect of the payload can be anything from a harmless message appearing on screen to the destruction of the disk drive's boot record.
