I've got it installed on my media machine only which is using Vista 32 Bit Home Premium; Antivir; SuperAntiSpyware & Malwarebytes and it seems fast enough. Mind you, I can't find anything on it, why do Microsoft insist on moving things about and then insisting it's better?
I'm starting to get haggled by Microsoft again to install IE9 on Win 7. No! Go away! It says 'Important update available' No it isn't - go boil your bottom Steve Ballmer and leave me alone.