Computer worms are considered to be one of the best weapons in a computer attacker's arsenal. Through these computer worms, evil-doers intrude into computer systems to destroy files, attack other computer systems, steal data and so on. The concept of a computer worm is not new; attackers have been using worms to attack computer systems for decades now.
I recently reinstall the OS in my Windows because I passed to another computer, it seems that the computer is slower than when I've just bought it new. I thought reinstalling OS would reset the computer to the initial speed. Are there any physical causes that can slow down computer irreverisibly?