From Wikipedia, "Spyware is computer software that is installed surreptitiously on a personal computer to intercept or take partial control over the user's interaction with the computer, without the user's informed consent."
Spyware results in system slow down and is most often noticed when your computer goes from being quick and responsive to taking excessive time to load common programs. You might also be bombarded by pop-ups and other irritating ads.
Once your machine is infected, often it is easier to reinstall your operating system rather than attempting to clean the system. Coding Horror: How to Clean Up a Windows Spyware Infestation is a good guide for removing malicious software. If you feel unsure about running the tools described there or damaging your system, your best bet is to bring the machine to the Help Desk.
If you'd like to try cleaning the machine yourself, please see the Malwarebytes article. It will guide you through acquiring, installing, and using the application. It is one of the applications that the Help Desk utilizes in order to rid machines of infections.