I use MSE on home netbook for the last two years.
German lab downgrades Redmond after zero-day detection rates slide
German lab downgrades Redmond after zero-day detection rates slide
Quote
Another security software testing organisation, Virus Bulletin, says Security Essentials’ performance is sufficient to justify its VB100 rating, which can only be attained by software that “prove[ s] it can detect 100% of malware samples listed as 'In the Wild' by the WildList Organization” without generating any false positives.



- carpe noctem
Aside of those AV tests, my setup has not experienced any infection yet and it is stable in my low-powered netbook.