updated 02:17 pm EDT, Thu April 17, 2014
Unclear if XP version of anti-malware utility will see an update
Widespread reports are circulating about problems with Microsoft's Security Essentials package for Windows XP. Users are claiming that the latest update is slowing machines down to a crawl, similar to the impact that an active virus would have on the machine.
The OS remains functional, and data is not being lost. On boot, users are reporting errors related to "MsMpEng.exe," forcing users to kill the process to regain computer control. A follow-up boot in Safe Mode is often required to terminate the process completely, and prevent the rogue process from restarting. Of course, preventing the application from launching also eliminates any malware protection as well.
So far, Microsoft has no comment on the problem. Given the discontinuation of Windows XP by Microsoft, it is not clear if another patch to the software will be issued.