Free antivirus, antispyware software often fails to protect computer systems adequately because the required virus definitions constantly need to be updated. That takes manpower to keep on top of it all, so free solutions usually don’t have the budget and hired staff to do the job. But now there is no real reason for users to lack the protection that security software affords.
Microsoft Security Essentials (MSE) is free antivirus, antispyware software created by Microsoft that provides protection against viruses, spyware, rootkits, and trojans for Windows XP, Vista, and 7. MSE has been tailored for home and personal use and replaces Windows Live OneCare (a paid antivirus subscription) and Windows Defender.
Symantec and McAfee, are claiming that MSE is not as effective as their own offerings and AVG Technologies views MSE positively, explaining that it reinforces the company's model of free antivirus software.
Public reaction has been mostly positive and reviews praise its simple, well laid-out interface, modest resource utilization, and Freeware license . (* See Video)