We have heard about reports that MS10-015 causes some Windows XP machines to blue screen. If you are seeing this issue, please let us know. (I am filling in for Deborah on this diary as she is ironically busy dealing with lots of blue screens in her organization, which may be related) See for example: http://www.krebsonsecurity.com/2010/02/new-patches-cause-bsod-for-some-windows-xp-users/ and http://social.answers.microsoft.com/Forums/en-US/vistawu/thread/73cea559-ebbd-4274-96bc-e292b69f2fd1 ------ Johannes B. Ullrich, Ph.D. SANS Technology Institute Twitter