Various common malwares like virus, worm, spyware all affect PC performance. A well performing PC is a secure one too. Although their affect is often more on the disastrous front than simple affect on performance, since we are discussing performance here, let us identify that part of the malwares affect.

Viruses and worms are known to slow down PCs. This is since they are doing their job while you are trying to complete yours. This has a significant affect on the resources of a PC and ultimately performance is much lower than otherwise expected.

Hence even from a performance point of view, you must take all the usual precautions against the common malwares. The steps are discussed in much detail in our PC Security guide. You are requested to check it out in detail.