Microsoft Security Essentials 4.4.304.0 – Final (always working and latest version)

Download Link 32bit

http://mse.dlservice.microsoft.com/download/A/3/8/A38FFBF2-1122-48B4-AF60-E44F6DC28BD8/enus/x86/mseinstall.exe

Download Link 64bit

http://mse.dlservice.microsoft.com/download/A/3/8/A38FFBF2-1122-48B4-AF60-E44F6DC28BD8/enus/amd64/mseinstall.exe

Offline Updates Latest Edition 32bit

http://download.microsoft.com/download/DefinitionUpdates/mpam-fe.exe

Offline Updates Latest Edition 64bit

http://download.microsoft.com/download/DefinitionUpdates/mpam-fex64.exe