I recently decided to upgrade my mid 2011 iMac from Mountain Lion to Mavericks, but as soon as I did my computer began to crash every ten minutes or so and give me errors saying I am low on memory even though I have 16 GB and have an app telling me I have 9 GB free. I could not find an easy solution so I tried to reinstall snow leopard with the disc in my iMac box. Everything went alright until it restarted and now all I have is a screen that looks like this: Nothing is clickable and I can't do anything at all. If anyone could offer assistance I would really appreciate it! Edit: If I wait about 10 minutes I can click things on the screen. However, when I click on my profile and try to log in. It will not accept my password.