On my real old XP Home system that has 2.4MHZ P4 and 512MB RAM I have not noticed ‘MsMpEng.exe’ sporadically grabbing large hunks of CPU time but next time I fire it up I’ll watch it with System Explorer.
I fired up the old XP Home system and watched System Explorer Performance window and ‘MsMpEng.exe’ used a bit of system resources to initialize but it has been quite ever since.
RAM usage is at 79% with IE8 with 5 tabs open.
Are you using the latest Windows Defender Antispyware: v1.57.85.0 available through its portal?
http://www.microsoft.com/security/portal
I update it at least daily as it is updated at least as often as avast! definitions and sometimes more
Top Desktop Threats
- Trojan:JS/Agent.FA
- Worm:Win32/Conficker.B
- TrojanDownloader:ASX/Wimad.BD
- Virus:Win32/Sality.AM
- TrojanDownloader:ASX/Wimad.AT
- Virus:JS/Xilos
- Worm:Win32/Roron.AA@mm
- Virus:Win32/Mabezat.B
- Worm:Win32/Hamweq!inf
- Worm:Win32/Conficker.C