So I installed Ubutu 13.04 alongside Windows 8 and after a week or so it stopped working and I couldn't figure out how to recover. I went back to windows for a little while and downloaded Ubuntu 12.04 to install that version. As I couldn't access the partition I had made for Ubuntu, I formatted it and then made a bootable USB with the iso. I went to bios to change the boot settings from UEFI and when I applied the changes it showed me "Unknown filesystem. Grub rescue" and won't let me Access to bios to go back to Windows and try to figure something out. Any help is much appreciated.
You need Windows 8 Recovery CD, you can make one by using specific option on Windows 8 or by downloading image of it (search google for guides). Then, make a bootable CD or USB (I recommend using WinToBootic) and repair boot - automatically or in command prompt (two commands: bootrec.exe /fixboot and bootrec.exe /fixmbr).