How do i know?

How do I know if I have spyware or malware on my pc? are they obvious? I'm not not the smartest cookie when it comes to these things, i dont have many programs installed on my comp, just the normal stuff, i was just wondering how i could spot it?

 

Most infections are obvious because they cause popups, they slow your internet speed and mostly slow your computer's performance.

Some of the new ones called "rootkits" are harder to detect but usually if you have this you have all of the others as well.