what do you mean, "load an image from windows" ?
select an image from your hard drive while the sketch is running ?
if that is what you want, take a look at this tutorial http://wiki.processing.org/w/Open_Files_through_a_GUI

I just discovered the sDrop library, it lets you drag and drop an image into processing.  Very Cool

yep, i was about to recommend that but you didnt ask for drag&drop ;)