Cos I'm nice, I found more details about Ubuntu for you.
http://www.ubuntu.com/desktop
It's a 'liveCD' meaning that you can reboot your computer with the CD and it won't touch any of your files.
The web page has a brief intro/ description.
Download link is at bottom of the page. Just download the CD image, burn it onto CD, check it works (try it out on any known working computer) then try it out on your laptop.
If it boots, you can then access your HD and save any important files to external storage (CD / DVD/ USB). After that, a full reinstall of OSX will be needed.
It seems that the Ubuntu LiveCD will work on any computer, PC or Mac. (correct me please if I'm wrong - the Ubuntu website isn't clear on this)
http://www.ubuntu.com/desktop
It's a 'liveCD' meaning that you can reboot your computer with the CD and it won't touch any of your files.
The web page has a brief intro/ description.
Download link is at bottom of the page. Just download the CD image, burn it onto CD, check it works (try it out on any known working computer) then try it out on your laptop.
If it boots, you can then access your HD and save any important files to external storage (CD / DVD/ USB). After that, a full reinstall of OSX will be needed.
It seems that the Ubuntu LiveCD will work on any computer, PC or Mac. (correct me please if I'm wrong - the Ubuntu website isn't clear on this)