Thank you so much for reading. I'm pretty desperate for an answer at this moment.
So anyways, I recently solved this issue allowing me to install xubuntu 12.10 correctly. This was a problem with the MBR. (even though I use EFI? :/ )
Now when I boot up the computer, I get to go into grub. OK. xubuntu works perfectly, no weird things over there. But when I try to boot Windows, there is this error: "error: invalid EFI file path".
(Both OSs are x64 and they also both use EFI.)
This is the log from boot-repair. I can't seem to understand why Windows won't boot :(
Any help is greatly appreciated!