Yet another Windows related article – this detour from more typical content is expected to be short lived.
Microsoft Security Essentials was never officially supported on 64-bit Windows XP, but version 2 nevertheless installed on it and worked fine. Version 4 (version 3 never existed) refuses to install directly, saying that the version of Windows is unsupported. However, if you install version 2, the version 4 installer will happily run and install version 4 as an upgrade. It will pop up a message every time you log in warning that XP64 is EOL, but otherwise it will work just fine. So the trick is to install version 2 and then upgrade to version 4.
You may be wondering why this is relevant. My findings are that most realtime anti-malware programs thoroughly cripple performance. I used to run ClamWin+ClamSentinel as one of the least bad options, but even this was quite crippling. MSSE, on the other hand, is much more lightweight, and has thus far proved itself to be as effective in tests as most of the alternatives. The overall performance of the system is now much more acceptable.