A computer security software, as the name suggests, is a software program which when installed into your computer, secures it from external threats such as virus, malware, spyware, botnets and the like. A computer virus is a program that attaches itself to files, and spreads from one computer to another during the process of transfer of files. Once a virus enters the system, it is not easy to remove it as it comes with the ability to replicate itself. A virus has the potential to damage the hard drive of your computer. An anti-virus software detects the presence of virus, and other related threats on your computer, and checks the spread of virus from potential sources such as spam, e-mails, web pages, pop-ups, etc. If you are using a Windows operating system, it is essential that you use an anti-virus software on your PC. It is estimated that there are about 70,000 viruses that affect Windows systems. Whenever you transfer files, browse the Internet or view e-mail attachments, your computer is at risk. Not only this, nowadays different types of computer crimes are on the rise, making it all the more essential for you to protect sensitive data. So, it is necessary that you use an effective anti-virus software to protect your PC from all kinds of threats. An antivirus program can be rated based on 6 factors: rate of virus detection, its effect on your computer's performance, how user-friendly it is, its features, its scanning speed and its price. Here you'll find reviews that will help you zero in on the best security software for your PC. It is the best computer security software in the market today and is compatible with Windows XP, Vista and Windows 7 (32 or 64 bit). It can correctly detect all known threats, providing protection from Trojans, worms and bot-nets. Real-time scanning of email attachments and files and protection of instant messengers like GTalk, are also a part of the package. It's light on the computer's resources, which means that its installation does not slow down your computer. Moreover it's user-friendly, easy to use, and the speed of scanning is pretty good. Priced approximately at $59.95, it is costlier than other products in this category, but you are licensed to use it on three PCs. This software can be used on a computer that is already infected with virus and malware and this program is built to restore the default settings of your system after the removal of the malicious program. This antivirus program is compatible with Windows 2000, Windows XP, Windows Vista and Windows 7 and can be used on only one PC. Its biggest advantage is that it is compatible with older versions of the Windows operating system. It has a feature called the ThreatSense that is very effective in the detection of new attacks of virus, adware, spyware, worms, etc. This program uses only 44 MB of space and is user-friendly. Its energy-sipping feature saves power and its built-in technology prevents malicious software from corrupting it. Not only this, the ESET Nod32 scans compressed files and operates so fast that you can work and even play on your PC while the scanning is on. Priced approximately at $39.95, this is the antivirus software to go for if all-round protection is what you seek. A product by Panda Security, the latest version of the Panda Antivirus Pro can be used on a maximum of 3 PCs. It is compatible with Windows Vista (32 & 64-bit ), Windows XP (32 bit) and Windows 7 (32 & 64-bit). This software comes with a very high detection rate, is extremely light on resources and has a user-friendly interface. In addition to this, it has other features such as scanning emails before they reach your inbox, anti-phishing filter, real-time scanning of files, scanning of instant messengers, among others. Its major drawback is its average scanning speed. However, its approximate price of $50 makes it a good buy. Priced around $40, this antivirus software is for use on only 1 PC and is compatible on Microsoft Windows 95, Windows 98, Windows Me, Windows NT 4 (No Server), Windows 2000 (No Server), Windows XP, Windows Vista and Windows 7. Its major advantage is its compatibility with the older Windows operating systems. It has a very high detection rate when it comes to detecting viruses, spyware and malware. It is very light on the resources and does not tax your PC's memory space. Its user interface is not appealing but is functional. It has a fairly high scanning speed and does not affect your computer's performance. Licensed for use on only one PC, the McAfee VirusScan Plus is compatible on Windows XP (32-bit) with Service Pack 2 (SP2) or higher, Windows Vista (32-bit and 64-bit) and Windows 7 (32-bit and 64-bit). It is priced around $40 and comes with an outstanding rate of virus detection, and a user interface that is stylish and appealing. It utilizes about 40-50% of the CPU resources during a scan, and so is not very light on the resources. Its interface has a built-in feature to rate the safety of websites with red, yellow or green color. In addition to this, it includes the regular features of antivirus software including email scanning, anti-phishing, anti-spyware and instant messenger scanning. Its slow scan speed, however, serves as the major drawback. Priced around $40, this antivirus software is a good choice. Before you choose a computer security software for your PC, it is highly recommended that you weigh the pros and cons of each brand. Hope the computer security software reviews discussed in this article, will be of help to you in your endeavor.