On Linux, with the latest official binary video driver from nVidia, I can use
mplayer -vo vdpau (and some other flags) to offload the video decoding to the nVidia GPU. Is there a free media player for Windows XP which can do the same? I have the latest official nVidia video drivers installed on the Windows XP.
VLC needs Windows Vista for accelerated video codecs, SMPlayer doesn't say that it supports them.