I Have only Fedora and want to Uninstall Fedora and Install Windows XP/7.
Shut down your Fedora system.
Now insert any linux distro cd which has live OS function.
I recommanded to use Ubuntu cd.
Now in menubar select System, then Administrative tools then Disk Utility.
In disk utility select a volume in which you have installed Fedora and format it.
Now you have to change partition