I exchanged the HDD in my 2007 MacBook Pro and removed the DVD drive because it was making a terrible noise every time I booted the MacBook.

The new HDD is a Corsair Force F120 SATA SSD. I formated it as HFS+.

Every time I try to launch an OS X Lion installation disk or USB stick I get the grey prohibitory sign and the machine shuts down after a while.

When I connect the old harddrive (with OSX still on it) I'm able to boot it up successfully.

Any ideas what is wrong?

2 Answers 2


it is greyed out because it is in the wrong file format => ntfs

you should use disk utility via the usb stick to format the drive to HFS+ and then you will be able to install on it

  • I connected the old hard-drive (which still has OSX on it) via USB and booted it up successfully. Then I formated the new SSD to HFS+. When I select the install usb-stick, the prohibitory sign still appears.
    – Hedge
    Commented Apr 12, 2012 at 19:03
  • Did you change the partition table from mbr to guid ?
    – Manuel
    Commented Apr 12, 2012 at 21:12

I found the problem myself when I copied the old system-partition to the new one via SuperDuper, then went to the AppStore to buy Lion.

The problem is that I own a very early MacBook Pro which only sports a Intel Core Duo. Since Apple dropped support for 32 Bit-only processors with OS X Lion it won't work.

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