Windows "missing operating system" after Ubuntu 12.10 instal?

I tried with both rEFIt and rEFInd, and I cannot access the grub loader menu. It says something about it being missing?

ok.
Please run Boot-Repair --> Advanced options --> "GRUB location" tab --> select "Place GRUB into: sda" --> Apply.
Tell me the new URL that will appear.
Then reboot and tell what you observe.

I tried that an I got the message:

"GPT detected. Please create a BIOS-boot partition (>1mb unformatted filesystem, bios_grub flag). This can be performed via tools such as Gparted."

via Gparted, reduce your sda4 partition in order to make 1MB free space between sda3 and sda4.
Then in this space, create a 1MB unformatted partition with bios_grub flag.
Then run Boot-Repair --> Place GRUB into sda.

Actually, I tried booting into Ubuntu via rEFInd and could find the GRUB menu, I just couldn't boot into my mac osx partition or windows partition from that menu...

Can you boot MacOS and WIndows from Refind?

Mac os yes, windows no. I can't boot into windows from any bootloader, they all say its missing the os.

Where you able to boot Windows before installing Ubuntu? if yes, how?

I did by holding down option, using the bootcamp bootloader, and choosing windows.

Then you should reinstall Bootcamp and check if you can still access WIndows from it.