Microsoft has confirmed that a recent security update (KB977165) may be causing restart issues for some Windows XP users. This update is no longer being issued through Windows Update, and Microsoft is investigating the root cause of these problems. If you believe you are experiencing problems due to this patch, a solution is offered Link Removed - Invalid URL.
MS10-015: Vulnerabilities in Windows kernel could allow elevation of privilege
MS10-015: Vulnerabilities in Windows kernel could allow elevation of privilege