Online is only good for 2021 now. You can't do a prior year return online or efile it, but you can buy the download desktop versions for the last 3 years from Turbo Tax here....
http://turbotax.intuit.com/personal-taxes/past-years-products.jsp
Or you can check for Turbo Tax for all years on Ebay or Amazon, etc.
Either way you will have to print and mail in your return. And if you are doing more than 1 year, send each year in a separate envelope. Sometimes the IRS will just staple all the sheets together and miss a second return. Be sure to attach copies of your W2s and any 1099s that have withholding on them. Don't forget state. You have to mail federal and state in separate envelopes because they go to different places. Get a tracking number from the post office when you mail them for proof of filing.
Or if you have a simple return you can get the blank forms from the IRS and fill them in by hand for free. I have a list of some of the basic ones I can post a direct link to.
For blank prior year IRS forms go to
http://www.irs.gov/app/picklist/list/priorFormPublication.html
