@kylin5 - if you properly backed up your computer, the data files from prior years all end in *.taxYYYY where YYYY is the tax year. the actual tax returns are in *.pdf files
if you purchased the software from Turbo Tax originally, you can download each year from your account on their website:
https://turbotax.intuit.com/personal-taxes/cd-download/install-turbotax/
note that you really can't set up the software for 2018 and prior on a new computer. 1) Turbo Tax does not maintain them on your account and b) if you have the original CD's, there is no way to download the updates from TurboTax.
