UK Internet users who visit the relevant Microsoft page are greeted by a message "Not available in your country or region. You appear to be in a country or region where the Microsoft Security Essentials Beta is unavailable."
Infosecurity can report that the software is downloadable if you are using America Online, whose client software routes the IP calls via its US operations centre.
Users of US proxy servers and the Tor Network may also succeed, Infosecurity notes, although it should be noted that users downloading the software from outside the US, Israel of China are in technical breach of Microsoft's software licensing conditions.
Microsoft is promoting the software as a basic antivirus/antispyware application that consumes less memory and disk space than commercial suites from the likes of Check Point's ZoneLabs operation and McAfee plus Symantec, and is therefore suitable for low-powered PCs such as netbooks.
Security Essentials runs on Windows XP, Vista, or Windows 7 - beta or release candidate versions.
Early reports are that the software does what most competing free IT security applications do, namely that it downloads virus and spyware definitions; supports real-time scanning of downloads and attachments, and looks for any suspicious activity on the PC.