Good morning, I recently (as in yesterday at 12:00 AM) upgraded a late 2009 MacBook Pro model (aluminum construction) to Yosemite. I upgraded it from 10.3 to Snow leopard via install disc. Then downloaded mountain lion via the app store and upgraded then to OS X Mavericks and then Yosemite. Yosemite worked for about 12 hours before things started to slow down. I restarted the pro to see if it would help. Alas it brings up the apple logo and loading bar and only gets half way before stalling and never moving a muscle. Please see attachment picture. I have tried resetting the Systems manager controller. I tried running the snow leopard install disc but my optical drive is broken. I used a external optical drive and tried booting with Snow leopard but still there is nothing but the loading bar and apple logo. When that didn't work I researched more and tried starting up in singer user mode with Cmd + S but nothing different happened. Frustrated and out of options. What can I do? Any assistance would be greatly appreciated.