Just be aware that backing up wirelessly was taken away from Windows Home 7 that was available in Vista Home now you either need a third party software or purchase Professional or Ultimate.
Ah I never used that feature in windows anyway. And besides even on both of my Mac's I get nothing but "Sparce Bundle" errors when trying to backup using time machine.
There's an easy fix for that -- reformat the TM drive and let it make new backups.