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?