Hi, lately I've been using Okular on Windows (last 3 months) to preview Latex documents. I'd like to see it added to the list of Windows PDF readers :) Okular unlike Acrobat does not lock the file, so I was able to compile the latex source and it would automatically get updated in the viewer. Installing Okular on Windows is pretty easy - just grab the installer from windows.kde.org and select kdegraphics to be installed.
Regards, Frederik