The comparison was made with data harvested in the first half of 2011

Oct 12, 2011 17:11 GMT  ·  By

Microsoft compared the infection rates on a number of supported Windows platforms, and unsurprisingly, the results indicate that Windows 7 Service Pack 1 is the best choice for customers looking for a secure OS.

x64 (64-bit) Windows 7 SP1 along with the x86 (32-bit) flavor of the operating system have the lowest infection rates out of all Windows releases, the software giant reveals in Security Intelligence Report volume 11 (SIRv11), which covers the first half of 2011.

“As in previous periods, infection rates for more recently released Microsoft operating systems and service packs are operating systems and service packs are consistently lower than older ones, for both client and server platforms,” Microsoft informs.

“Windows 7 and Windows Server 2008 R2, the most recently released Windows client and server versions, respectively, have the lowest infection rate.”

Users of x64 Windows 7 SP1 have experienced the fewest infections, at a rate of just 1.1, followed by those running x86 Windows 7 SP1 with 1.8.

According to SIRv11, the infection rates for 32-bit and 64-bit Windows 7 RTM were more than double that of Windows 7 SP1, 4.0 and 2.7 respectively.

“Infection rates for Windows XP SP3 and Windows Vista declined following the February 2011 release of an automatic update that changed the way the AutoRun feature works on those platforms to match its functionality in Windows 7,” the company added.

Here are the infection rates for additional Windows platforms, x86 Windows XP SP3 – 10.9, Windows Vista SP2 5.7 (x86) and 4.4 (x64), Windows Server 2008 R2 RTM – 3.6.

“The information (…) was compiled from telemetry data that was generated from more than 600 million computers worldwide and some of the busiest online services on the Internet. Infection rates are given in computers cleaned per mille (CCM), or thousand, and represent the number of reported computers cleaned in a quarter for every 1,000 executions of the Malicious Software Removal Tool,” Microsoft revealed.

Windows 7 Service Pack 1 (SP1) RTM Build 7601.17514.101119-1850 and Windows Server 2008 R2 Service Pack 1 (SP1) RTM are available for download here.

Windows 7 RTM Enterprise 90-Day Evaluation is available for download here.

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