An update of McAfee's AV software appears to have stuffed up a number of users' PCs.

Forums show that it's affecting McAfee customers in Germany, Italy, and other parts of the EU. One user had half the machines he looked after knocked out when he upgraded his network. The update identified winvnc.exe and several other legitimate files as malware and attempted to quarantine them.

Without these systems files the computer was effectively a brick. The glitch appears to be caused when older VirusScan engines install DAT 5664, which McAfee seems to have pushed out over the weekend. The list of files the software hates include files belonging to Microsoft Internet Explorer, Compaq drivers and the McAfee-associated McScript.exe.

With America closed for the holiday weekend it seemed that there were few attempts to fix the problem.