Does turbotax archive or have backup on prior years of tax files? If they don't what is the purpose for purchasing "AUDIT DEFENSE" Package?

[DoninGA]

If you used the desktop CD/Download editions installed on your computer, the only copy of your tax data file and any PDF's will be on the computer where the return was created.  TurboTax does not store online any returns completed using the desktop editions.

All TurboTax returns started with the online editions are stored and available to the creator of the online account.

[TXWhiteHat]

"Online Editions", please clarify...CD bought at Sam's or Target, or a download from Intuit. After losing 2016 returns completely, as in no trace left on computer (not even 2016 desktop Icon), although 14 and 15 are still there w/data makes me really wonder what happened. 2014 was a CD, 2015 was a Amazon Prime download and is still here, 2016 was an Amazon Prime download and has disappeared. Already tried account-recovery and the "try something" else doesn't provide any real answer.

[DoninGA]

Any tax returns started or completed using either the CD or Download software installed on your personal computer are not stored online by TurboTax.

Any tax data files or saved PDF's will be on the computer where they were created.  The TurboTax program would normally store any tax data files and PDF's in Documents and in the TurboTax folder.  Unless the default storage location was changed by the Administrator or a Windows upgrade moved the files to another location.
If the PC was upgraded to Windows 10 then the files may be in the Recycle Bin.  If not then do a wild card search of all local, external or networked drives for the tax data file.  The 2016 tax data file has a file extension of .tax2016, but you should use the wild card search using *.tax*