Microsoft Security Essentials gives real-time protection for your home or small business Computer, which protects against viruses, spyware, and digital malicious software.First, Identity, your computer has a 32-bit or 64-bit Version, then Visit the official site and click the Download button on this page to start the download, after choosing a language from the drop-down list and then click on Go.Click on the Start button, now right-clicking to the Computer menu, and then select Properties to open the System Properties.On this page, Under the System heading, you will view the system type page.Once you have checked and confirmed which operating systems version you have using, now download and install the respective version of Microsoft Security Essentials.