Consider using memory resident virus protection software. Remember that even the best anti-virus software will have to be regularly updated since new viruses are being created all the time. Make a bootable virus recovery disk with up to date anti-virus software and write protect it to keep it from becoming infected. This disk must be made while your system is not infected with a virus, once you have a virus, it is too late and you may have to go to another computer to make an anti-virus disk. Also, keep up to date backups of your programs and documents to minimize any loss in case you do catch a virus.
Viral infections can manifest themselves in many different ways depending on the type of virus.
If you suspect your computer is infected with a virus, proceed with caution and in a slow methodical manner. If you are unsure what to do, get help from someone more experienced. Often data is needlessly lost by panic driven drastic steps such as reformatting a hard disk. This is often unnecessary and in the case of boot sector or partition table viruses will not even remove the virus. Don't backup over your good backup When faced with the discovery of a potential virus on their computer, many users' first reaction is to backup their data to prevent any loss in case the virus becomes destructive.