Security Links:

Owning and operating a computer comes with the responsibility of keeping it up to date and secure.
Infected PCs are not only a threat to themselves and their owners, but also to everyone else that may come in contact with them.
Plus, infections may cause your system to slow down or become unstable.  And privacy concerns  stem from  infected system possibly transmitting data to unknown sources.
Take some time and learn some basic principals of security and the tools needed to help do your part to keep your PC healthy.
Below are some resources that will help.
Note that you will find many FREE alternatives so there really is no excuse for not getting it done.   
Remember, as security goes up, usability goes down.  Yes, it can take a bit of time, but the alternative can be much more costly.

 

Anti-Virus, Security, Malware removal, Adware Removal, Spyware Removal Software:

Product/Vendor Name: Type of Product Free Online Scan Available? **Free Downloadable Version Available?
AVAST AV + Security No

Yes

Avira AntiVir AV + Security No Yes
BitDefender AV + Security

Yes

Yes (On demand scanner ONLY!)

F-Secure AV + Security Yes No (Trial Version available)
AVG (Grisoft) AV + Security No (tools available) Yes
McAfee AV + Security Yes No (Trial Available)
Panda AV + Security Yes No (Trials  Available)
PC-Cillin (Trend Micro) AV + Security Yes No (Trials Available)
Ad_Aware (LavaSoft) SpyWare/Adware Removal No Yes
SpyBot Search and Destroy Spyware/AdWare Removal No Yes
Malwarebytes Malware Removal No Yes
C.A. E-Trust Security Suite Yes No (Trials Available)
OutPost Firewall (Agnitum) FireWall No Yes
Microsoft Security Essentials AV No Yes
Virus Total Single File Multi-AV Scanner YES No
Symantec (Norton) AV + Suite Yes No
ZoneAlarm (ZoneLabs) FireWall & Suite No Yes