what's the microsoft security is on the computer
Microsoft Security Essentials. Microsoft Security Essentials (MSE) is an antivirus software (AV) product that provides protection against different types of malicious software such as computer viruses, spyware, rootkits and Trojan horses. Before version 4.5, MSE ran on Windows XP, Windows Vista and Windows 7, but not on Windows 8 and later, which have built-in AV components.