CWmike writes "Microsoft said today that computers in countries with high rates of software piracy are more likely to be infected because users are leery of applying security patches. 'There is a direct correlation between piracy and the malware infection rate,' said Jeff Williams, head manager of the Microsoft Malware Protection Center. Highlighting research that showed worms to be the most prevalent computer security problem today, Williams said the link between PC infection rates and piracy is due to the hesitancy of users of pirated software to use Windows Update. China's piracy rate is more than four times that of the US, but the use of Windows Update in China is significantly below that in this country. Same for Brazil and France. But Microsoft's own data doesn't always support William's contention that piracy, and the hesitancy to use Windows Update, leads to more infected PCs. China, for example, boasted a malware infection rate — as defined by the number of computers cleaned for each 1,000 executions of the MSRT — of just 6.7 per thousand, significantly below the global average of 8.7 or the US's rate of 8.2. France's infection rate of 7.9 in the first half of 2009 was also below the worldwide average."