Are returns done with downloaded turbo tax not retained on the web site? I need my AGI from 2017 and none of my returns are shown. My machine crashed & no physical copy

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.

You can also get free transcripts of your federal return from the IRS - http://www.irs.gov/Individuals/Get-Transcript

For a fee of $50 you can get a complete federal tax return from the IRS by completing Form 4506 - http://www.irs.gov/pub/irs-pdf/f4506.pdf