Works on: Windows 95 / Windows 98 / Windows 2000 / Windows XP / Windows Vista / Windows Vista x64 / Windows XP x64 / Windows ME / Windows NT 4.0 / Windows 7 / Windows 7 x64 / Windows 8 / Windows Server 2003 x64 / Windows Server 2003 / Windows Server 2008
Updating Security Essentials or Defender still won’t be possible, because no more updates exist. However, once manually installed, these definitions can always be used to scan your PC for malware.