After a roll-out to 19 countries, Microsoft has revealed some stats relevant to the release of its Security Essentials security software.

In the first week Microsoft saw well over 1.5 million downloads of the security suite, but admits "the price (free to Windows users) is hard to beat!"

As far as successful detections goes, Microsoft says up to 6 October it's seen almost four million detections on 535,752 distinct machines.

In terms of the OS split, 33% of downloads were to XP machines, 23% to PCs running Vista and a whopping 44% of downloads were on machines running Windows 7.

Microsoft says overall its seem "far more detections per XP machine, with the fewest from Windows 7".  

Ahead of the general release of Windows 7 on 22 October Microsoft states: "this follows our usual observed trend of seeing less malware on newer OSes and service packs".