Some time back I had to install Ubuntu on my laptop, because we need it for a certain course in school. I struggled a lot back then to get it on my MacBook, turned out I just had to change some boot options (noapic, nolapic etc). I was happy everything worked but then I made a mistake...

I went to see under additional drivers if there were any, and I saw an Nvidia driver. I installed it an restarted my laptop. Ubuntu wouldn't boot anymore. In the meantime I've formatted all partitions, so I'm basically back to zero, with only my Macintosh HD space (and some unallocated meant for Ubuntu).

Because I'm on a recent Mac I need to use refit. Although Ubuntu and its Linux swap are totally gone, I still see 'boot Linux from HD' in rEFIt. When I try to run Live Ubuntu or install Ubuntu from a USB (like I did the first time) I get the menu, I change boot options but then after the loading screen I get busybox, something I've never seen before.

I really hope someone can help me, my exam is in a week and I'm getting desperate...

Thanks in advance!

I have a MacBook Pro 15" 9,1 (non-retina)
2.3 GHz Intel Core i7 (Quad Core)
Intel HD Graphics 4000 (chipset) + Nvidia 650M (dedicated)
Running OS X Mountain Lion 10.8.2