We tried to install the Zune Software on Microsoft Windows XP 64 bit Professional edition. The software at the beginning of the installation searches for an update for some seconds. But after that it does nothing. It just throws the photograph with the 3 girls and says it needs an update or the windows need an update.

EDIT: We have found a solution to do this (thanks to kristof's comment below): Zune on Win XP64 Pro