The damage that a virus can do can range from overwriting information in the hard disk to scramble numbers in your spreadsheet. A virus will multiply itself and take memory space, slow your internet connection , slow the computer itself and diminish her performance. While some viruses appear to be harmless they should be eradicated from the system anyway as they can cause multiple errors on the computer just by being present. Other viruses will only activate after a certain condition is met causing severe damage.

Viruses can enter your computer in any of the following ways: email attachments, www sites, by downloading files from the internet, using other people’s diskettes, using pirate software and sharing files across the net. The most common points of entrance for a virus are email, floppy disks, internet connection. Another thing is the faster your connection is the most vulnerable you are to virus attacks on the net.There thousands of viruses across the net some of them infect certain operative systems more than others. The most common type of viruses are :boot viruses, file viruses, macro viruses.