User /System Permissions none.(Set to 000) A previously called friend of mine (As for now, after this he is no longer called that way) was messing up with my computer without my knowledge , and ultimately he set the System folder permissions to be 000 for all files in it.

Well, as I realized everything froze and as soon as I restarted the computer it won't go pass Apple screen, however I'm able to run gnome on it. Is there any way I could reset the permissions for that entire folder anyhow? Or if there is not, is there any way I could extract some files on the hard drive? I'm completely desperate.
Boot into single user mode (hold ⌘S on boot), then enter:

mount -uw /
chown root /
chmod 1775 /
exit


This will reset the permissions for the entire drive and all its contents allowing full read and write, and may take a long time — don't interrupt it. Once you are booted back in, go to Disk Utility and do a permissions repair to set the permissions correctly per OS X.