This is the list of resources related to Antiviruses or anti-spyware/malware tools. These resources offer basic protection or detection of the viruses and malware. For more specific tools, check our other Security resources.

Legitimate anti-virus and Internet Security software

Antivirus is a critical program for a PC today. Each day tons of new viruses and malware are created and distributed through internet, CDs, USB-enabled devices. Even worser, many of these threats appear in legitimate websites due to infections or unmonitored advertisements. Only an antivirus with scheduled updates and real time protection can protect a PC from majority of these parasites. There are 2 categories of these tools: Internet security software and antivirus only. For protection, internet security versions are recommended.

ESET Smart Security Software
ESET is the creator of our favorite Internet Security engine and Antivirus. We are using NOD32 (or smart security) antivirus protection for 4+ years and we are happy with it.
AVAST Internet Security Suite
Free Antivirus Download
AVAST offers one of the best free antiviruses around. Thus it is quite a good choice for basic protection from viruses and some types of malware. AVAST Internet security version is paid one, though there are deals to get one free for first year.
AVG Antivirus (Free)
AVG Internet Security
AVG makes one of the most known free antivirus and quite good Internet Security version. Sadly, free version of AVG antivirus has some functions limited (no rootkit detection/protection for example), thus I would recommend using other free product. There was some controversy with its detection and protection ratio, and there are some disagreements between testers.
AVIRA Avira Free
Security Suite
Microsoft Security Essentials MSE Download Microsoft Security Essentials is surprisingly good free antivirus consider Microsoft record for security products. The single problem is that it is not available in all countries.
Kaspersky Kaspersky Antivirus Trial
Internet Security Trial
Kaspersky releases antiviruses and internet security software for many years. Although we do not use it personally, we still recommend it as a good choice.
PCTools Free Antivirus
Internet Security
PC Tools offers a free antivirus and complete internet protection suite as well. While we can not recommend free antivirus due to lack of modules available in paid versions, the internet security version is very good as well.
Webroot Webroot SecureAnywhere Antivirus
WebRoot SecureAnywhere Complete 2012
Antivirus series by Webroot. It is very well know antivirus and anti-malware company.

Online system scanners

Although Online system scanners do not provide real-time protection, they are valuable on identifying and cleaning threats on infected PC. These tools require working network connection and might require some add-ons installed on PC.

ESET ESET is one of my favorite antivirus programs. The best of it is that it has free online antivirus scanner. The scanner requires administrative privileges to run.
HouseCall Housecall by TrendMicro was long-time favorite antivirus scanner and it remains good and valuable tool today.
OneCare Onecare by Microsoft is a good antivirus and tuneup scanner. It not only cleans some viruses, but helps in tunning the users PC. It works on IE/Firefox only.

Remote Computer Repair and Tune-UP companies

Remote PC Repair replaces a need to carry your PC over hardware shop. A technician connects to the PC over internet and fixes the problems. However, there are lots of scams related to repair shops thus one has to pick the company carefully, or you might be scammed.

Comodo’s LivePCSupport Comodo is one of leading security companies and offer computer repair and tuneup help. You can either subscribe to service or purchase one-time repair. The repair is initiated over chat.
CrossLoop Crossloop is a community/service of computer consultants. You can allow them to connect to your PC and repair it.