One day I was turning on the computer, and it simply wouldn't turn on. Ubuntu would start to turn on, but froze up/quit just as it was "loading the dots" on the Ubuntu boot up screen (Plymouth). It doesn't get past that, and I have files I need in Ubuntu that I obviously cannot retrieve using Windows. If anyone knows how to access Ubuntu files from Windows then I can just get my files and then re-install Ubuntu. Someone told me this was a bug in the last update and said to 'use an older date' when turning it on, but there's no option for this in my boot up screen.
You should be able to recover your files by booting your computer from a LiveCD/USB, then mounting your Ubuntu partition from Nautilus (the file manager). Once you have access to your files, just insert another removable data storage device of your choice to back your files up to, then unmount both and reinstall.
When someone told you that this was being caused by a bug in a recent update and to use an older version, it sounds like they think the kernel is the problem and you should try booting an older kernel. Assuming you haven't been removing them manually, you should be able to select the next highest-numbered kernel in your GRUB menu (12.04 LTS and previous), or find this kernel hidden in the "Advanced options for Ubuntu" entry (12.10 and later).