Gamer issues after Windows Security update 2859537 August 13, 2013
MS13-063: Vulnerabilities in Windows kernel could allow elevation of privilege: August 13, 2013
Known issues with this security update
Some users may experience issues with certain games after they install security update 2859537. In some cases, users may not successfully start and sign in to the games. Microsoft is researching this problem and will post more information in this article when the information becomes available.