If you find a virus in your system and can establish precisely what it is, it is a time to remove it from your system. Having procedures in place to detect viruses is important is a plan for how you will remove what ever you find.

you must remember that the majority of virus alarms turn out to be false alarms, and are the result of some user , software ,or hardware error , proceed with your detection assuming that although it may be a virus , it just as likely to be something else , so note all symptoms carefully and see what the combination point to.

If the problem turn out to be a virus, it is still important not to panic. You need a cool head to minimize further damage and to remove the virus as cleanly and efficiently as possible, don’t just get out your copy of FORMAT or FDISK and start formatting the hard disk.

Using an Anti-Virus Product

Most antivirus products offer virus removal capabilities. Usually these functions are built into the scanner, giving you the option to remove a virus from a file the moment it is detected in the file. Removal of some viruses is fairly straightforward for antivirus products can remove some viruses, but can’t remove very many. When choosing a product, ask whether the product can remove all common removable viruses.

Some viruses can’t be removed, no matter how clever the author of the antivirus software. This is because the virus has overwritten some of your original program, effectively erasing it. Without knowledge of what was supposed to be where the virus "sat down" all an antivirus product can do is offer to delete the entire program.

Virus Detection Strategy

If the virus is detected in the memory, but not in any file, and if the virus detected is an extremely rare virus, ask yourself whether another scanner that leaves in memory the scan string it was using can produce a false alarm when another scanner runs.

if the virus is detected in only one program on your hard disk , ask your self how often you have used this program ,If you have used it several times in the past , then any virus it has had an opportunity to infect other files, if it has not done so yet, it probably a false alarm , don’t delete the single program in which the virus was reported and don’t attempt removal, instead , reboot from an uninfected , write protected floppy disk and run another scanner to determine if it too finds something in this file . If it doesn’t assume that it is a false alarm.

If the virus is detected in several programs you use commonly, you almost certainly have an infection. Do not attempt to remove the virus product yet! You may cause irreparable harm to your files.

Protecting computers from viruses

Simply, do not give out your email address to widely, and never access a floppy disk given by someone you don’t know. Plus there is a load of antivirus software available which can help detect and clean out viruses, but then remember, virus programmers are driven by the desire to stay ahead of this kind of software.

PREVENTIVE MAINTENANCE OF COMPUTER SYSTEMS

There are three things one can do to prevent viral infection in a computer system. These are:-

1. limited sharing of software

2. limited transitivity

3. limited functionality

one can limit sharing by limiting information flow so as to form a post office set of communicating information domains in a network system , in such a system , a virus will spread only to those domains which are in the transitive flow path from its initial source.

in a system with unlimited sharing by limited information paths, limited transitivity may have an effect if users do not use all available paths, but since there is always a direct path between any two user , there s always the possibilities of infection . as an example , in a system , with transitivity limited to a distance of 1, it is safe to share information with any user you trust without having to worry about whether the user has wrongly trusted another user.