Spyware is a type of software often installed unexpectedly by a computer user. The author of the software uses spyware to cause advertising pop-up messages to be displayed on the victim's computer or to gather information about visited Web sites. Common programs for removing spyware include Ad-aware, Spybot Search & Destroy and Spyblaster.

Viruses are malicious programs designed to damage files on a computer. They are often spread through e-mail attachments, peer-to-peer file sharing programs, and instant messaging programs. Most viruses spread to other people through a victim's address book by sending out e-mails to contacts without the user ever knowing it. To avoid such vulnerabilities, install an anti-virus client such as Symantec's Norton Anti-Virus, McAfee Anti-Virus or Grisoft's AVG.

One of the most overlooked solutions to computer slowness is heat dispersion. All electronic equipment generates heat, and computers (especially newer computers) generate more heat than most devices. The warmer a computer's processor is, the slower it will compute. Excessive heat can even cause damage to the equipment. Users should make sure that the exhaust fan(s) on the back of the system can adequately vent hot air out of the system's case. Stacking papers, books, etc. around your computer can insulate it causing heat issues. The same precaution holds true for printers, DSL modems, and various other peripherals.

New software is generally designed on the pretense that the consumer will have new equipment. If you purchase and run new software packages on an old computer, you may experience slowness issues. Depending on the age and hardware specifications of your system, you may be able to upgrade your system's RAM, processor, or other components to significantly increase performance.