This guide is not mine but its a great one so I tweaked it a little original post can be found here:
Dual Booting the Wind – OSX and Windows 7*|*Gear Diary

Windows XP and OSX work well beside one and other but OSX and Windows7 /vista are A pain to install on 1 hard drive that's because the bootloaders cant work together there always fighting for dominance. Easy way to fix this by installing a 3th party program that's boss to them both.
this guide for this guide to work we have to start from scratch, or install to an empty partition.
what do we need:
windows 7 dvd
OSX dvd
boot cd : nawcom, iboot kakewalk empire efi or just a distro it will all be good.
easyBCD


Step1. Partition the Drive
Boot from your bootCD usb stick or what ever and boot the OSX DVD.
After setting the language the top bar off your screen will get text go to the utilities and
partition the drive with Disk Utility. Insure that the Windows partition is first, and is formatted as FAT32. After that, if you want to have a data partition or simply use the rest of the drive for OSX, that’s up to; but that should be formatted as FAT32 as well so both Windows 7 and OSX can read and write files to and from it. The OSX drive should, again, be formatted as HSF+ (Journaled). Remember osx and windows 7 cant natively swap out files. so a small data partition could be handy.


The point is that you can partition the drive any way you want, as long as the drive is partitioned with MBR and the FAT32 Win7 partition is at the top of the drive map.



2. Install OSX
When the drive is partitioned the way you want, quit Disk Utility and install OSX. When that’s done, boot into OSX to insure that everything is good do the after installation package , multibeast or what ever needs to be done to make it bootable.

3. Install Windows 7
When you get to the point where Windows 7 wants you to pick a drive to install Windows 7 to, the install routine will tell you that you can’t install Win7 to any of the drives you’ve got. Pick the intended drive for Win7 and reformat it as NTFS. You’ll then be able to move forward with the install.

Restart the PC as necessary. The computer will boot into Win 7. Please note that you will NOT see OSX at this point. Don’t worry. The install is still there.

4. Set the Windows 7 Partition as the Active Partition
When you finish, boot from win7 DVD and select repair. Select CMD (last choice) when the Command Prompt opens, type the following commands:

Diskpart
DISKPART> list disk
DISKPART> select disk 0
DISKPART> list partition
DISKPART> select partition 1
DISKPART> active
exit
exit

note it could be that the drive number is not correct it depends on if you have more then one drive and its place on the controller.
Now, off the main menu, select repair (first choice). Once you’re done, reboot. You’ll be taken back into Windows 7 again.

5. Download and install EasyBCD
EasyBCD is a bootloader, like the Darwin Bootloader that comes with the Wind compatible OSX install. However, unlike GRUB, Darwin, or even the bootloader that comes with Windows 7, its got a GUI interface; and its very easy to use.



After EasyBCD is installed, follow these steps. Please make certain you are logged in with Administrator privilages:



Click the Add Remove Entries button
In the Add an Entry area, click the Mac tab.
Click the Type Tab. Select Generic X86 PC
In the Name dropdown, use the name NST Mac OS X
Click the Save button in the upper right corner

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6. Restart the Computer
When you restart the computer, you will see a boot loader screen. Hit the down arrow to choose the OSX entry you just created. Hit the enter key. You’re going to be taken to the Darwin Bootloader. Hit any key to stop the counter, and scroll to the OSX install, and the computer should boot to OSX.

That’s it… good luck to you