Unfortunately, after October of 2016, Turbotax for 2012 is no longer available or supported. There is a time limit to file an original or amended return to get a refund. That time limit is 3 years from the original due date of the return. The time limit for filing a 2012 return to get a refund expired in October of 2016.
If you need to file a 2012 return for reasons other than to get a refund, you can get the forms and instructions for free from the IRS website, at this link:
http://www.irs.gov/app/picklist/list/priorFormPublication.html
