Hello, this is my 1st post

I install Windows 7 and create a partition for Mac OS.

Now, in Mac OS install i have formated the partition with Mac system file but i can't install. The installer don't let me go ahead because i don't have a GUID partition table.

I've downloaded the OSInstall.pkg and i replace the original by the modified, so, i burn the DVD and try to install but it still requires a GUID partition map schem don't let me install at MBR.

What i did wrong?