First, read the definitions of each to understand what they are and how they spread. Most infections occur from intentionally or unintentionally downloading programs or from opening email attachments. Additionally, without proper protection, infections can be spread from computer to computer without web browsing or email.
 

Most common SpyWare infected systems will exhibit poor performance such as increased CPU usage, lack of available RAM, and/or slow response time. Additionally, pop-up ads or browser redirection indicates that SpyWare has hijacked your computer. Viruses are often undetectable because they may require a trigger (such as opening an infected file) in order to initiate. However, once active, viruses may or may not exude symptoms. Damage can range from minimal to catastrophic depending on the nature, but noticeable signs of infection can include application errors, blue screens, failure to boot OS, missing or corrupt files, improperly functioning hardware or software, and many other things.
 

Although results from an infection vary from case to case, one of the most common side effects is application configuration changes. This is usually attributed to file and/or registry modifications or deletions. Using SpyWare cleaners and Anti-Virus software will most likely correct problems, but some applications (including Windows) can become so corrupted that they require reinstallation.

Although it's best to avoid infections in the first place by running anti-virus and anti-spyware applications, computers that are connected to the internet will most likely become infected at some point. If your prevention software fails to block an infection at first, full-system scans may eliminate the threat. Otherwise, special tools that target specific viruses/spyware may be successful. In the most extreme cases where significant damage has been caused, reformatting the computer and reinstalling the operating system may be the only available option.
 

The best defense is practicing safe web browsing and download habits, so here are some tips that may help:
 

	Tip #1: Trust Only download files from sites you trust. If you're not sure whether or not to trust a file, then do some research on the source. Additionally, don't trust a site only because it is well known - infections can come from reputable sources.
	Tip #2: Firewalls While most SpyWare and Viruses come bundled with other programs or originate from unscrupulous Web sites, targeted infections can occur remotely by hackers. A firewall is a good first line of defense against hackers.
	Tip #3: Software Legitimacy Read all security warnings, license agreements, and privacy statements associated with any software you download. Don't download and/or install software that you believe may not be legitimate or safe.
	Tip #4: Closing Pop-ups Never click "agree" or "OK" to close a pop-up window. Instead, click the "x" in the corner of the window or press the Alt + F4 buttons on your keyboard to close a window.
	Tip #5: Downloads Be wary of popular "free" music and movie file-sharing programs, and be sure you clearly understand all of the software packaged with those programs. Frequently, downloaded music or other shared media will contain viruses. Only download from a trusted source.
	Tip #6: Email Attachments Don't open email attachments from unknown sources or that contain file types you don't recognize. Most malicious attachments are .exe files, but sometimes just opening an email can cause an infection.
	Tip #7: Prevention Let a Click I.T. SpyWare and Virus expert shield your computers before an infection has the chance to take hold. We'll verify your safest settings, install software protection, and train you how to detect and clean a possible infection.

A general term given to programs that intentionally and deceptively intercept data and/or partially take control of a computer without the user's consent. As opposed to most viruses, SpyWare does not replicate itself and is designed to exploit infected computers for commercial gain. Typical tactics include tracking browser activity, stealing personal information (such as credit card numbers, email addresses, etc.), redirecting web traffic, and pop-up advertisements.
 

Term given to programs that display advertisements through pop-ups or web browsers, with or without the permission of a user. SpyWare often contains Ad-Ware components. However, Ad-Ware is designed primarily for commercial gain.
 

Malicious code that exhibits behavior similar to viruses, worms, or trojans and deliberately performs actions that ruin or alter files or applications. Unlike SpyWare and AdWare, MalWare is capable of replicating itself and can spread to different computers, making it an increased threat. MalWare is not usually designed for commercial gain and is often disguised in other software, such as shareware or freeware.

Software code that is dependant on a host file/program and can carry out arbitrary code. A virus is capable of reproducing, but only through the reproduction or transmission of the host file/program.
 

Similar to a virus but is capable of operating independently from a host and can spread on its own. Most worm infections occur from trickery or false pretensive actions, such as clicking on a phony ad.
 

Harmful software that disguises itself as being legitimate. Trojans cannot replicate, but like worms, they are often spread through deception and trickery and can contain other harmful code such as SpyWare or MalWare.