dunno what windows will do when its installed, im not a windows user, ask one of them(if they even know)
however, its a really simple matter to use any drive partition program to delete the mac filesystem and install another one of your choice
chances are good that windows will not be able to delete the mac partition, the microsoft version of fdisk will not deal with other filesytems that arent microsoft
id do this one of two ways, temporarily put the drive in a linux box and remove the mac partition, or boot up a linux "live" cd like knoppix in the windows machine with this new drive connected and remove the mac partition that way
most non microsoft boot disks(floppy or CD) will easily do this,and without disturbing whats on the windows machine already
