October 10 marks the end of the line for Windows XP Service Pack 1, which will no longer be supported by Microsoft as of that date.

Though the vast majority of Windows XP users have migrated to Service Pack 2, released two years ago, lately there has been an uptick of interest in Service Pack 2 migration issues on patch-management discussion lists, said Susan Bradley, chief technology officer with Tamiyasu, Smith, Horn and Braun Accountancy.

"There are still people out there using Service Pack 1," she said.

Those who haven't made the move may be running specialised applications that do not support Service Pack 2 but this kind of legacy software issue is usually less pronounced with client operating systems like Windows XP, said Chris Andrew, vice president of security technologies at PatchLink.

"Now pretty much everybody is running Service Pack 2, so I don't think there's going to be a significant outcry," he predicted.