Imposible continue with the installation of Snow leopard 10.6 on a 1TB external hard disk. I did the same last year and I continued working but suddenly appeared the simbol with a folder and a question mark and I know this is a problem so I click in the format option to the hard disk and when I tried to install again Snow Leopard, 'cause I want to recover my backups with Time Machine, I couldn't continue because the installation didn't respond to the click in the Utilities option or to next step > continue . Please, What can I do? I'll wait for your answers. Thank you so much in advance.