Microsoft has fixed an issue with its antivirus definitions in Microsoft Security Essentials that was causing some Windows XP PCs not to boot up earlier this week



From Neowin:

Microsoft has since released new definitions for MSE and the other programs that support the download, so the booting issues with Windows XP should now be resolved. In a blog post, Microsoft said, "While the issue primarily impacted customers running Microsoft security products on Windows XP and Windows Server 2003, it may have also impacted other supported operating system versions." So anyone who is running MSE on their PC might want to go ahead and grab the new update.

  Microsoft fixes issue that caused some Windows XP PCs not to boot up