Joe Faulhaber of the Microsoft Malware Protection Center has made the interesting claim that 64-bit Windows 7 is actually safer than ordinary, 32-bit Windows. He’s right. “64-bit Windows [does] has some of the lowest reported malware infection rates in the first half of 2009.” But, that’s not the whole story.
Why? As Faulhaber explains, “Computer viruses are very confused by 64-bit. Taking a look at 64-bit executable code detected by Microsoft anti-malware technologies in the past month, the vast majority is innocent 64-bit files infected by 32-bit viruses. While a 32-bit virus can only see other 32-bit processes, it unfortunately can see the file system, and can tamper with files it finds there.”
That’s the good news. The bad news is that this works only because malware makers haven’t been targeting 64-bit Windows. 64-bit Windows XP and Vista both had stability problems and good old regular 32-bit software often had problems running on it. Because of this few people ran either one.