i have ScientificLinux 6.5(64 bit) installed just fine on a HD with win7
mind you i let win7 have the MBR and the first section of the drive
( the only way to win the "war" is to NOT play MS's game)
and grub is installed on the FIRST linux partition
and the bios is set to auto boot from grub and NOT win7
On installing,it said 'This hardware is not supported on Centos" but i stil continued and then it said not enough space though i have 80 Gb allocated for it.
i am guessing you did not read the "dual boot" install instructions
and you tried to install cent into the Windows hidden "recovery partition"
and did not reformat the drive to make room to install a second OS
CentOS uses the redhat docs
RHEL6.5 install guide