Vista with certain games actually requires about twice the normal requirements to play.

so if your game requires 512 mb ram to play on vista it'd require 1gb Don't ask me why but that seems to be the case with many games... it might apply to WLO also as I notice I can only play about 3-4 windows without lagging despite my vista laptop being about 4 times more capable than my xp desktop which can play 2 windows without much problem.