There was nothing wrong with that security update in February, the few people that had a BSoD had rootkits on their systems. http://www.msfn.org/board/kb977165-t141817-pid-908314.html/page__view__findpost__p__908314 http://www.msfn.org/news_story/microsoft_says_malware_causing_blue_screen_crashes.html If you're getting a BSoD on XP, Vista, and 7 you probably have bad hardware, as that would be a single common factor whereas having a bad configuration on all 3 operating systems is less likely. An easy way to review the dump files create by the BDoD is with NirSoft BlueScreenView (freeware) http://www.nirsoft.net/utils/blue_screen_view.html If you post a screenshot of that program window or upload the actual dump files we might be able to help you determine the cause. You may want to run a Memory Diagnostic anyway, Memtest86+ (freeware) is recommended http://www.memtest.org/