This is by far the best advice any security expert can give you. No anti-malware device can offer 100% detection rates. You are the best anti-virus. Always understand what the motive behind advertising free software is: it can be either to advertise a paid version of the product or such, or it can be spyware (serve ads on your PC as means of financing the author). Be wary of free smiley packs, toolbars, antispyware products, etc.

• Understand the EULA - Let's admit it, most of us skip the EULA (license agreement). After all, there can't be malware there. Well, you'll be surprised. Many malware vendors choose to spread their programs using "legitimate" methods, so as to avoid legal trouble - e.g, there is an ad on a certain site, your attention gets caught by the ad - you download the software and install it right away without going over the EULA, only to discover that there are ads popping up on your desktop, and no, they can't be removed through Add/Remove programs. That was written in the EULA… EULAlyzer will help you with this by analyzing key phrases and sentences that talk about possible advertising, limiting of rights, privacy violations and more. It will point you out suspicious sentences, and there's not need to read the EULA itself. EULAlyzer by JavaCool software (Freeware)
• Always GOOGLE before downloading - There is a lot of malware out there, concealing in legitimate software. So, before you download any kind of software: Google it. If the software is legit, there shouldn't be any mention of it on security forums and anti-virus vendors. If there is, don't download and/or install it.
• Watch what you download - Many people download cracks to bypass protection in software and games, and make it "work" as if it were legit. Besides the legal factor, by far this is the most common method of infection. Especially beware of files called crack.exe, keygen.exe, serial.exe and such. Watch what files you download through P2P (Peer To Peer) software.
  • Free antivirus - There are several free solutions on the market. They all are good anti-viruses. Avast! 4 Home Edition (requires free license registration), Avira Anti-Vir Personal , AVG8 Free. Occasionally, you may also want to scan your computer to get a second opinion, using an online scanner that won't interfere with the local anti-virus software, such as Kaspersky Online Scanner.
  • Free anti-spyware - MalwareBytes Anti Malware (MBAM): combines real-time monitoring with excellent detection and removal rates.
  • Free firewall - Comobo Free Firewall: provides excellent protection and is also light on the system. ZoneAlarm Firewall: offers good protection with a large set of tools, but is heavier on the system.

The Holy 3

In this case, the more is NOT the better. If you install multiple anti-virus programs and firewalls, you are guaranteed to get sluggish performance, false positives and lesser detection rates, since each anti-virus program will conflict with the other. Same for the firewall, but not for anti-spyware software - it's OK to install more than one anti-spyware product, but I recommend staying with one. Never download unfamiliar anti-spyware, firewalls or anti-virus software, and if you do - Google it first and find reviews of it. Many of these are considered rogue, and once installed - will detect false positives and nag you to purchase the software using annoying popups.

When Unsure - Scan

If you have downloaded a file, and you suspect it - don't open it. If not triggered by another process or user input, downloaded files will usually remain inactive. Scanning it with your local anti-virus will not give you definite results, and you should scan the file with an online scanner, which uses tens of virus scanners to check the file for known infections (and unknown ones, using heuristics). Two such websites are Jotti s Online Malware Scan and VirusTotal. While nothing can guarantee the safety of a file, scanning the file with one of these online facilities gets close.

If All Hell Breaks Loose - Ask The Experts

There are a lot of volunteer websites online that will help you to remove malware online (even tough ones!) using community-developed tools that are not commercially available or automated, for free. The help is professional and friendly, but remember that the helper's response can take time, depending on the helper's and website's workload. GeeksToGo, BleepingComputer are two such boards which I personally like. There are a lot of others. Be sure only to post in one board, so as not to waste multiple helpers' time. You can find more links to such websites here,