Can I file previous years on Turbotax?

You can't do a prior year return online or efile it, but you can buy either the cd or download the 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 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.

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