Most of the time, when we are not careful with our body, we get infected by viruses which mess up with our immune system and impede us from functioning well. These viruses can lead to several complications, from simple colds to a life-threatening condition. And, not surprisingly, our computers are also bothered by viruses, not of course the kinds that humans catch, but the effects are quite the same. The computer viruses vary from something fairly harmless to possibly serious, which could cause your computer to just slow down or eventually crash, just like their biological counter-parts.