WAH BAT WAH !!
amazing guide ... kudos to u
and no i aint spamming
why ?
lets add a security software guide and a lil more info on security threats shall we ?
if i may ofcourse !!
DEFINITIONS:
A Biological Virus: an entity that attatches itself to a healthy cell and uses the infected cell to infect other cells
a computer virus works in a similar way
it NEEDS to attatch itself to something before it can infect and spread
there has to be a mechanism to run this virus automatically
this is explained below
Malware: MALicious softWARE, including viruses, worms, Trojans, Denial of Service and other such attacks. Sometimes referred to as rogue programs
Denial of service (DoS) attacks: cause thousands of access attempts to a Web site over a very short period of time, overloading the target site and shutting it down.
Identity theft: is the impersonation by a thief of someone with good credit.
Macro viruses: are viruses that spread by binding themselves to software like Word or Excel.
Malware: is malicious software that is designed by people to attack some part of a computer system.
Worm: is a computer virus that spreads itself, not only from file to file, but from computer to computer via e-mail and other Internet traffic.
How A Virus Can Attach / Two Types of Virii
1.) Boot-Sector Virii: infects boot sector executables. affects MBR's / Partition Tables .
once its loaded in the memory .. it sits and waits
2.) Macros / Macro Virii: A macro is a series of commands and instructions that you group together as a single command to automate a task.
Go
Here for more
Guide To AntiVirus Software :
an extensive shootout performed
Here
Detailed Reports:
Here in .RAR format
im posting the top 10 with final rank ( acc. to how many virii out of the 76556 it detected ) here:
Code:
1. Kaspersky Personal Pro version 4.5.0.58 - 99.09%
2. F-Secure 2004 version 4.71.5 - 98.77%
3. Extendia AVK Pro version 11.0.4 - 98.68%
4. AVK version 14.0.7 - 98.50%
5. Kaspersky Personal version 5.0.149 - 97.88%
6. eScan 2003 Virus Control version 2.6.484.8 - 96.75%
7. McAfee version 8.0.41 - 93.59%
8. Norton version 2004 Professional - 93.38%
9. RAV version 8.6.105 - 93.14%
10. F-Prot version 3.15 - 91.85%
Steps that should be taken ?

use IE's inbuilt pop-up blocker and Info Bar (IF ur still using IR and SP2 Required)
tho most of the browsers have pop up blockers now .. for those still on IE and SP1 u can use
MSN Toolbar
Google Toolbar
other software like POP UP COP
in my experience the latter 2 were VERY effective

block activeX components ( set them on 'prompt' )

use a better browser

like maxthon (still based on IE tho), FireFox, Opera [top 3]

use a firewall.
zone alarm and sygate are good personal firewalls
then in shareware u have
NIS, McAfee's Firewall and ZoneAlarm the PRO version
personally i think ZAPro rocks ... i put my trust in it
get ZAP tips
Here
personal firewalls compared
Here

use a good AV . ( this should be a top rankin point but i already covered an AV shootout )

spyware adware removers L like adaware and spybot like bat mentioned
in addition other good ones are
BPS ( Bullet Proof Software ) spyware remover<== i love this. got immunisation for 150 threats for ur browser. Plus inbuilt HiJack This
Spyware remover
spyware doctor

speaking of HJT learn how to use it and use it well
here

DO NOT neglect trojans ... DO Treat them as SEPARATE YET MALICIOUS threats
DO use separate Trojan removers like Anti Trojan Shield
Other links:
Spyware Glossary but we have a better one here
Some More Spyware Tools recommended from Download.com
DISCLAIMER: i am not responsible for the quality of this post
it was written in half hour
i have made a lot of repeat points from bats post ... ive just made a few additions
be safe