Microsoft has told beta testers of its free antivirus software that it will release the final version to the public soon.

In an email Sunday, Microsoft thanked beta testers for their help and said that the polished edition of Microsoft Security Essentials would ship "in the coming weeks". Microsoft also urged beta testers to upgrade to the newest version of the test software to make the transition to the final as smooth as possible.

In June, Microsoft issued the beta of Security Essentials to about 75,000 users, but quickly shut down the offering when that target was reached.

Microsoft has touted the software as a basic antivirus, anti-spyware product that consumes less memory and disk space than commercial security suites like those from vendors such as Symantec and McAfee. It is the company's replacement for the former Windows Live OneCare, a for-a-fee security suite that was retired at the end of June 2009.

Although rival security vendors have dismissed Security Essentials - once codenamed "Morro" - as proof that Microsoft couldn't compete in the paying market, some analysts have been optimistic about its chances.

Microsoft has also said that it would block users running counterfeit copies of Windows from downloading Security Essentials. "Nongenuine users are really difficult to defend," Alan Packer, general manager of the company's anti-malware team, said in June about the decision.

Security Essentials will run on Windows XP SP2 or later, Windows Vista and Windows 7. When it does go final, the antivirus program will be available for downloading from Microsoft's site.