A big problem, if there show up errors, on Windows are often ATI's OpenGL drivers as they just suck. They are better on Vista than on XP. If it's not running under Vista then there something else seems to be wrong.
Keep in mind that the webplayer only is supported for Safari (not 3 yet), Camino, Firefox and IE. If you're using FireFox then you also have to turn off the feedback setting as otherwise this slows down played content a lot ( this counts for every content and not only Unity).
Secondly fullscreenmode (via right mouse button) is faster than windowed and well that's about it. You can check if you have a general problem by trying out some stuff also from my tryouts ( http://spielwiese.marune.de/_uni/index.html ). If you can't run some stuff there too then it seems that really something is going wrong on your system with unity...
Keep in mind that the webplayer only is supported for Safari (not 3 yet), Camino, Firefox and IE. If you're using FireFox then you also have to turn off the feedback setting as otherwise this slows down played content a lot ( this counts for every content and not only Unity).
Secondly fullscreenmode (via right mouse button) is faster than windowed and well that's about it. You can check if you have a general problem by trying out some stuff also from my tryouts ( http://spielwiese.marune.de/_uni/index.html ). If you can't run some stuff there too then it seems that really something is going wrong on your system with unity...