An anonymous reader writes "Starting on April 15th, an update pushed out by Redmond triggered problems logging into PCs running Security Essentials on Windows XP. The problem arises when users try to login and receive a memory cannot be read error related to MsMpEng.exe. The PC will usually freeze at this point. While the PC can be started in Safe Mode, Microsoft does not allow Security Essentials to be uninstalled in safe mode. My solution with several PCs has been to boot into safe mode and disable Security Essentials using the msconfig utility. Security Essentials can then be disabled by unchecking a checkbox on both the Services and Startup tabs of this utility.
Microsoft promised antivirus support with Security Essentials on XP until 2015. Is this a conspiracy to break PCs or an honest mistake? Discussion at XP Forums (http://www.xpforums.com/bug-microsoft-security-essentials-lames-windows-xp-t931878.html) and Fudzilla (http://www.fudzilla.com/home/item/34518-microsoft-security-essentials-bug-kills-xp-boxes) confirms this is NOT an isolated problem."