When it originally debuted, Panda Cloud Antivirus was notable as a free security solution for two reasons: Panda traded on its reputation as a solid security suite vendor making its first foray into the realm of freeware, and the program attained its goal of freeing up system resources by putting much of the program’s heavy lifting in the cloud. Now we can add a third reason to the list: it’s now known as an effective alternative to the security powerhouses.

When you open Cloud Antivirus, the main window lets you know whether you’re safe or not with a big red or green icon. Cloud Antivirus works as other antivirus solutions do, offering a Quick Scan and a Custom scan for specific folder, files, and drives, but its ancillary features are exceptionally light. You can opt out of contributing anonymous data to the cloud, but that also opts you out of automatic threat management. There’s a network connection proxy option should you need it, and a reporting feature that will show you what kind of threats have been detected and removed from your computer. You can filter the report by All, Last 24 hours, Last Week, or Last Month, and there’s a Recycle Bin pane from which you can recover a false positive, should you need it. The modest level of tweaks and customizations have been hidden behind an obnoxious “flipping” screen that cheesily rotates when you need to access it, but they do provide choices in a clean UI that weren’t available before.

Size : 302 KB

Microsoft Security Essentials (MSE) is a free antivirus software product created by Microsoft that provides protection against different types of malware such as computer virus, spyware, rootkits and trojan horses for Windows XP (x86), Windows Vista, and Windows 7 (both x86 and x64). Microsoft Security Essentials replaces Windows Live OneCare, a commercial subscription-based antivirus service and the free Windows Defender, which only protected users from adware and spyware. Unlike Microsoft Forefront family of enterprise-oriented security products, Microsoft Security Essentials is geared for consumer use.

Microsoft Security Essentials received positive reviews upon its release.

Size : 7.1 MB

Avast! Antivirus is an antivirus program developed by AVAST Software a.s. (former ALWIL Software a.s.), a company based in Prague, Czech Republic. It was first released in 1988. Avast! is based on a central scanning engine that is certified by ICSA Labs and West Coast Lab’s Checkmark process and incorporates anti-spyware technology, also certified by West Coast Lab’s Checkmark process, as well as anti-rootkit and self-protection capabilities. It is a multiple recipient of the Virus Bulletin VB100 Award, for detection of 100% of “in-the-wild” viruses, and is a past winner of the Secure Computing Readers’ Trust Award.

Avast! Free Antivirus is the freeware version of Avast! antivirus software available to Microsoft Windows and Linux users, while Avast! Pro Antivirus is offered to businesses and users that want additional features. Priority updates are delivered automatically using PUSH update technology in Avast! Pro Antivirus. Avast! Pro Antivirus also has a command line scanner and a script blocker.

Avast! Antivirus is a widely used antivirus program, with 100 million users worldwide as of December 2009.

Size : 51 MB