Since the end of support for Windows XP, strange things happen on some computers with the formentioned operating system using Microsoft Security Essentials.
First Microsoft informed the world that MSE would still be supported (read: updated) on XP until July 2015, but since April 10th the system tray icon of MSE has turned RED (and stays red!) to tell us after every boot up that the computer is not protected anymore because of the end of support for XP. Microsoft is not only misleading users with this message but frightening them as well. I call this unacceptable!
Secondly another - more crippling - problem has arisen. I am a professional computer engineer and maintain many desktops and laptops for my customers on a daily base: as of today (April 16th) I have seen about 12 computers on which Windows XP - after every boot up - throws up an error message referring to MSE, stating: "MsMpEng.exe application error. The instruction at "0x5a4d684d" referenced memory at "0x00000000" The memory could not be read", leaving the computer in an unusable state, because it won't go on anymore, whatever you try, and the only solution is to disable MSE or uninstall it completely (if a user who is not a computer engineer knows how to do that anyway!). This I call even more unaceptable!!
I'm not suggesting that Microsoft is doing this on purpose, but I can't imagine that this situation is coincidental.... And how is Redmond supposed to fix this problem when those computers are not responding anymore, apart from the fact that updates and hotfixes are no longer offered?