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Free Antivirus Comparison: Avast vs. Microsoft Security Essentials

written by: Donna Buenaventura•edited by: Lamar Stonecypher•updated: 5/19/2011

An antivirus program should not only protect a computer but it should be able to work along with other applications and provides ease of use. In this article, we compare Avast vs. Microsoft Security Essentials.

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    Microsoft Security Essentials and Avast are free antivirus programs for personal use. Both programs will protect, detect and remove the computers against malicious activity or processes that can damage the system, other applications and posing privacy risks of your data or personal information. Find out which of these two programs suits your needs.

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    System Requirements, Installation and User Interface

    Avast and Microsoft Security Essentials (MSE) runs on XP, Vista and Windows 7. The setup file of MSE is smaller than of Avast, 4.28MB vs. 41.5MB. Avast’s installer is bigger than MSE because it includes several protection components that you can customize during the install process. Avast’s installer also includes an unnecessary installer of a browser, Google Chrome. A computer reboot is not required to start using the protection offered by both programs. The hard-disk space used by Avast is also bigger than MSE: 112MB and 10.4MB, respectively.

    During the installation process of MSE, the setup wizard will try to check if the copy of Windows to install the antivirus program has passed the genuine validation. Avast on the other hand requires an e-mail registration to proceed using the free antivirus protection.

    Windows 7 and Vista are shipped with Windows Defender by Microsoft that will be disabled by Microsoft Security Essentials installer. Avast will not disable Windows Defender during and after the installation of the antivirus program. Both products will succeed in reporting their status to Windows Security Center or Windows Action Center.

    The UI of Avast 5 has a lot of improvements from the earlier version, Avast 4.0. The media player-like UI of Avast is now replaced by a neat UI with easy access to its product features and options. The tray icon of Avast has been changed to one icon only. The UI of MSE is simple to use and its icon in the systray of Windows is animated like Avast. The handy commands in using Avast are easily done from its icon while MSE is only provided via its notification icon, an option to open the program.

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    Features of Avast and Microsoft Security Essentials

    All of the features in the antivirus program by Microsoft are provided by Avast except the following:

    • Mail Shield – Avast will scan the content of incoming and outgoing e-mails for malware. It can also scan messages that are retrieved using SSL protocol. MSE will only scan e-mail attachments.
    • P2P, Network and IM Shields – Avast will protect end-users using P2P and chat programs and also provide protection in a network shield that will automatically block malicious URLs and known misleading and rogue websites. The Network Shield of Avast also includes an intrusion-detection system.
    • Silent or gaming mode – using any applications requiring a full screen mode or if you are a gamer, Avast will continue the protection but will only disable the on-screen notifications. This will ensure that Avast will not interfere while you’re playing games or using any software in full screen mode.
    • Behavior Shield – like MSE, Avast also provides a behavior-based protection but you can adjust the sensitivity of the behavioral detection to be used by Avast.
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    Product Updates, Scan Timing and Memory Usage

    Both antivirus programs offer free program and definition updates. Avast and Microsoft are allowing its customers to also download the definition updates for manual installation via their respective websites.

    Avast vs. Microsoft Security Essentials memory usage: While using the computer for other tasks, there’s not much difference on the memory usage by both programs. Avast will use 2.7MB while MSE runs 3.1MB of memory. However, Avast will use more memory during a scan:

    • Avast will use 7.7MB of memory while running a scan
    • MSE is only using 4MB of memory during a scan process

    A quick scan using Avast will finish in 12 minutes with 22,707 tested files. MSE’s quick scan lasted only in 3 minutes with 41,847 tested files. A full system drive scan by avast is faster than MSE:

    • Avast have scanned 427,576 files in 28 minutes only
    • MSE has finished scanning in 47 minutes with 465,594 tested files.

    Issue: I noticed some minutes of freeze in the computer whenever MSE is installing its latest definitions for viruses and spyware. This is happening only during the install but not the download of the definitions.

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    Protection and Detection by Avast vs. Microsoft Security Essentials

    Using a unique 85 malware samples, Avast will protect more than MSE:

    • Avast is able to catch in real-time, 75 out of 85 malware
    • MSE’s real-time protection only caught 65 out of 85 malware

    However, during an on-demand scan using both programs, MSE is able to detect more than Avast:

    • MSE was able detect another 6 out of the remaining 20 malware samples.
    • Avast found no more infection on the remaining 10 malware samples that it failed to detect.

    The total malware detection by MSE is 71 out of 85 malware while Avast will protect and detect against 75 out of 85 malware. That’s a neck to neck score!

    The independent antivirus testing lab, AV-Comparatives has awarded both products with:

    • Microsoft has received 2 Gold awards (low false positive rate and good on-demand malware detection) and 1 Bronze award (malware removal). It has gained four Advanced+ ratings during 2009.
    • Avast has received 1 Bronze award for the fast scan speed and has gained three Advanced+ ratings only during 2009.
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    The Bottom Line

    Both programs are offering the best possible protection and ease of use but in this comparison, Avast has outperformed Microsoft Security Essentials’ features and protection. Avast's network shield is very useful which Microsoft should consider adding on their free antivirus program.

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