Microsoft will launch a free anti-malware beta service today. The new service, called Microsoft Security Essentials, will replace its Live OneCare product. The new service will run on Windows XP, Vista and Windows 7 and will be available in a limited number of countries, including the United States, Brazil and Israel. The company also plans to make a simplified Chinese version later this year. Malware is one of the primary drivers for Windows security enhancements.

MSE Replaces Live OneCare

Microsoft Security Essentials will compare signatures of known malware products with file downloads to determine whether the user is inadvertently downloading malware. If the downloaded file passes the first test (no malware signature match), Microsoft Security Essentials will check its Dynamic Signature Service to see if any new malware signatures match the download. If the download seems like it may be malicious, the DSS will request a code sample to create a new malware signature. New signatures will be published three times daily. If users of the new MSE enable auto-updates, their computers will be protected automatically, even from hours-old malware releases.

In addition to being able to detect and reject malware downloads, the service can sniff out root kits and other malicious code that could impact a computer. The service scans the PC when the CPU is otherwise idle so it does not interfere with the normal operation of the computer.

MSE may not make nice with other anti-virus programs you may have installed on your computer. Running MSE and another antivirus product simultaneously will cause MSE to send up a warning about the unnecessity of running more than one anti-virus program.

Do you really need MSE? MSE might be a good idea for you if you have no other anti-virus or anti-malware program on your computer, or you’ve stopped updating the program you have. It’s always a good idea to have anti virus and anti-malware programs on your computer.

I’m not sure I agree with the “wisdom” Microsoft puts forth when it warns users about not needing more than one anti-malware program. Some malware programs are just better than others, and malware can be notoriously difficult to track down. Having one semi-competent anti-malware program loaded and running may give users a false sense of security about how well their computer is protected. There are multiple anti-malware programs that work well together, but MSE will have to prove itself as reliable before I’ll tell anyone that it’s the only anti-malware program they’ll ever need.

Photo Credit: Wildernice, via Flickr