is this windows "XP" or "Vista" or "Windows7"
the reinstall for the windows bootloader is different for each
see the MS website for that
as to fedora -- well "fedora 15 BETA" is the BETA TESTING ONLY
version for TESTING only
and there will be bugs
But fedora is normally good at detecting windows XP and VERY VERY iffy for 7 ( the OEM's put a "recovery partition" on the front of the drive)
edit the grub.conf and change the option for "other" from ( just GUESSING HERE ) [hd 0,0 ]to [hd 0,1]
you can find out by running
this is ALL explained in the fedora docs
fedora never did use a "recovery partition" nor uses a "recovery option"
If you need to use the Install dvd in "recovery mode " or in "single user mode"