Here's what I did and it worked.
1) Used win7 assistant to transfer all my files to another place (i used an external HDD)
2) booted from win7 setup DVD, formated. (Now, the bootloader is the Microsoft's Default)
3) Opened windows update and updated and installed everything (drivers and etc)
4) Restored my settings from the Windows 7 migration assistant as being a new pc
5) Opened the Windows 8 Setup and selected option to update installation without changing the files.
6) used Unibeast to boot at Mountain Lion Partition, and opened Multi Beast and installed (updated) chimaera
7) Rebooted and chose Unibeast to boot from USB, then chose Disk Utils, unmounted the Mountain Lion Partition.
8) Closed Disk Util, and opened Terminal and entered this command:
"dd= if=/Volumes/USB/usr/standalone/i386/boot1h of=/dev/disk0s2"
Now everything works fine and I have my Windows 8 and Chimaera Bootloader working.
Note that I could just use windows 8 DVD to format and reinstall, but, I don't know about you guys, but my Windows 8 license won't activate if I install it from zero. I have to perform an update. Thats so idiot but, that's what Microsoft said to me when I gave them a call to complain about this. Despite the fact that you can install Win8 from zero, you won't be able to activate it because Windows 8 it's an Update, not a Standalone OS (again, that's what Microsoft Brazil said via phone support when I asked them why my win8 license was not working).
Anyways, thank you for the support!
*********** NOTICE****************
I discovered a way for activating windows 8 with your purchased key from zero. Actually, it's pretty simple.
1) After using the windows DVD/Pendrive to wipe your windows partition and stuff, you just have to:
a) Winkey + R and type: Regedit
b) Search for HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE
c) Double click on the key "MediabootInstall" and change it from 1 to 0
after that, you'll just have to go to start menu (Metro Menu) and type: cmd (right click and run as admin)
and for the last, type: slmgr /rearm and press enter
that will work! you'll just have to restart windows and it's all there.