I recommend keeping at least the
last 4 year of tax returns to your hard drive as a PDF well as backing up
the tax data file for each year to a removable storage medium. You'd need
that if you ever were to lose data and needed to amend your return.
Here are links to instructions:
https://ttlc.intuit.com/questions/1912466-how-do-i-save-my-return-as-a-pdf-in-the-turbotax-for-...
https://ttlc.intuit.com/questions/1912403-how-do-i-back-up-my-tax-file-in-the-turbotax-cd-downl...
