Adware is the less-malicious cousin of spyware. Often “adware” is designed to simply pay attention to your browsing habits at certain sites or kinds of sites and tell a server someplace what kinds of ads and other information to include on the pages shown to you.

In this sense – the most generous view – it is a form of personalized marketing, and because these things started as ad-serving assistants they are called “adware” even now, when many of them track your behavior, which is one problem, and slow your web connection to a crawl, which for many of us is the real main problem.

If you order from a clothing company a few times a year, you may well not mind if there is a cookie from that company that makes sure you see the sale items you’re likely to be most interested in – but if that cookie is slowing down your ability to work, you may well want to get rid of it anyway.

Helping to distinguish between truly friendly cookies and other “spyware” and the bad stuff is something we’ll cover shortly.

First let’s take a look at viruses, then the more vexing and current problem of spyware and its many guises.