Help! OS X install failed - can't access Mac

[Memory]

Hi all,

I have just installed OS X Yosemite but during the install I get: ' OS X could not be installed on your computer
File system verify or repair failed.
Quit the installer to restart your computer and try again.'

I have tried three times to restart the computer, but I keep getting the same message. I am kind of desperate at the moment what to do as I really need to use my mac for uni today and have no idea how to access the normal interface. I don't mind going back to Mavericks I just want the mac to work :-(

Anyone any ideas?

 

[Memory]

I made a back up with time machine, but no idea how to run it if I am stuck in the 'install interface'

 

[honestone]

It would be good to know what specific Mac model you are having these issues with, and what OS you tried upgrading from.

IN any event, this article can help you:

http://www.macworld.co.uk/news/mac/how-do-i-restore-my-mac-time-machine-3449071/

Before doing the restore, you'll need to first erase, format, and if necessary, partition the internal drive on the machine. From the article, it looks like you can do that from Recovery Mode.