Download Microsoft Security Essentials 4.1.509.0 prerelease
Microsoft has released a ‘preview’ of version 4.1 of Security Essentials. Microsoft has been offering this free antivirus solution since September 2009 and since version 2.0 there is also a firewall in the program. The system requirements for this English-only trial version only mention Windows XP, Vista and 7, so Windows 8 is notably absent. Also, Microsoft has not announced what changes it has made in version 4.1.
| Version number | 4.1.509.0 pre-release |
| Release status | beta |
| Operating systems | Windows 7, Windows 7 x64, Windows XP, Windows XP x64, Windows Vista, Windows Vista x64 |
| Website | Microsoft |
| Download | |
| File sizes |
10.27MB – 12.60MB |
| License type | Freeware |