Hello!

Yesterday my macbook has stopped recognizing its hard disk, so I have entirely formatted the hard disk using Linux and now I'm trying to install only Linux on my Mac.
Now I have just installed Backtrack 4 using the whole hard disk but on startup grub doesn't start (pressing command button nothing happens and after a few seconds appears a blinking folder with a question mark). However the installation is ok, in fact if I start the bt cd and I select the option "Boot the First Hard Disk" the system starts perfectly. So it is only a boot loader problem...

Can anyone give me some suggestions?
Thanks (and sorry if my English isn't very good... )