boilerbill0: If you needed to amend your return & you did not want to fill out the form manually you would need the desktop version for that year & your .tax file with all your original information in order to prepare the amended return. If you did not have your .tax file you would have to enter all your original information first then do the amended return.
In order to calculate a correct amended return you would need the desktop software for that year (each year tax laws, forms, credits etc change). If you install a desktop software older than TurboTax supports for updates (fours prior years plus the current year) then your amended return may not prepare correctly.
