On a laptop with 2 disks and UEFI/Legacy I installed
- Windows8 using the whole second disk and UEFI (no secure boot)
- TC7 using the whole first disk and UEFI (no LVM + default
partitioning)
Both OS boot (using UEFI disk selection via F12) and work but
there is no entry for Windows8 in the F18 TC7 grub menu.
Please report a bug against grub2 and put "F18Blocker" keyword into Blocks field
[1].
Thanks.
[1] The installer must be able to install into free space alongside an existing clean
single-partition Windows installation and either install a bootloader which can boot into
the Windows installation, or leave the Windows bootloader untouched and working
https://fedoraproject.org/wiki/Fedora_18_Final_Release_Criteria