First off, so you don't confuse people, Canonical releases all their Ubuntu versions in April and October (4th and 10th months). Versions are numerically named for the year and the month. So you are either using 14.04 or 14.10. If you actually have 14.06 you have a very unique version.
You should be able to get the "code" name (something like Kinky Kitty) for your Ubuntu version from /etc/issue.
I believe that the numerical name will be in /etc/ubuntu_version. I may be wrong but it is something close to that. I no longer allow Ubuntu on here so I just am not sure.
/etc/issue should definitely exist and the code name will tell Ubuntu users what you are using.
/etc/debian_version is used in Debian and gives me in my Wheezy (Debian 7) install;
Your driver reinstallation proceedure will depend on what driver you are using. We do not know that as you give no information on your hardware.
What video card/controler are you using?
Are you using the proprietary driver?
Are you using the default FOSS driver?
That first question is crucial.
If you don't know the answer to the others you are using the FOSS drivers that are installed by default when you install the OS.