• What is spyware?
• Anti-spyware
• How anti-spyware works
• What to look for in an anti-spyware package?
• Cost
• Spyware removal
• Scanning options
• Proactive prevention
• Things to avoid

A considerable majority of PCs connected to the Internet are currently estimated to be infected with some kind of spyware, although many instances of infection may be from low-security risks like cookies. Anything that you can download for free -- and even some things that you pay for -- may have spyware included. In some cases you can get a spyware carrying version at no cost or pay to get a spyware-free version.

Peer to peer (P2P) applications are probably the best known carriers of spyware, perhaps unfairly since many, if not most, of the popular P2P applications do not carry spyware. While these have declined in popularity in recent years, the number of machines affected by spyware built into software like Kazaa is massive.

Here's a quick breakdown of the spyware risk involved in different types of free downloadable applications:

• Very high risk applications include free downloaded screensavers, media players, desktop icons and "smiley" emoticon packages, desktop assistants, digital pets (such as the infamous Bonzi Buddy) and other desktop "enhancements". These are packages that children, in particular, are inclined to download because they're "cute". Quite simply, these programs should be avoided at all costs -- they're nearly guaranteed to carry spyware.
• Medium risk applications carry a moderate to good chance of carrying spyware, although often with these packages its presence is more explicit; that is, they tell you about it when they're installing it. Peer to peer applications (most notably Kazaa, BearShare, Imesh, LimeWire, Grokster and Morpheus), free utility programs (such as FTP clients, firewalls or file managers) and small downloadable games fall into this category.
• Low risk applications include packages from major software vendors such as Microsoft, Adobe, Symantec and the like, along with open source applications hosted at places like SourceForge. While open source applications rarely carry spyware, on some occasions unscrupulous individuals have compiled and re-packaged open source applications with spyware.