I am not sure where you are reading this, but it is simply not the case.. There is no Time Machine for windows.. never has been.. never will be.. TM is totally locked to the Mac format of the disk.. Windows cannot handle HFS+.
You should also exclude any bootcamp partition from TM on the OSX.
You need to download or purchase a proper windows backup software, unless you use Win7 pro or ultimate. No home version of the windows software can do network backups.
There are so many backup softwares available for windows it is best if you read up what is most suitable for you.