Windows users running 64-bit versions of the operating system are less likely to get infected by attack code. According to Microsoft’s security team said that 64-bit Windows has some of the lowest reported malware infection rates in the first half of 2009.

According to the Microsoft Malware Protection Center 64-bit malware is still exceedingly rare in the wild. Based on data gleened from Microsoft’s Malicious Software Removal Tool (MSRC) the 64-bit version of Windows XP was 48 per cent less likely to be infected than the 32-bit edition during the first half of 2009; PCs running Vista 64-bit, meanwhile, were 35 per cent less likely to be infected than Vista 32-bit.

The blog said that that Windows 7 64-bit is the dominant flavor of that new OS as he touted its security. The blog claims that 64-bit Windows was safer by design than the less-powerful 32-bit version, ticking off such measures as PatchGuard, which makes it more difficult for malware to tamper with the operating system’s kernel.