What did you purchase?
If you purchased one to the TurboTax desktop editions for a prior tax year from this TurboTax website, the installation file should be at the latest level - https://turbotax.intuit.com/personal-taxes/past-years-products/
Or is your personal computer OS not compatible for using the TurboTax software?
See this TurboTax support FAQ for the Windows minimum system requirements - https://ttlc.intuit.com/community/system-requirements/help/minimum-system-requirements-for-turbotax-...
See this TurboTax support FAQ for the Mac minimum system requirements - https://ttlc.intuit.com/community/system-requirements/help/minimum-system-requirements-for-turbotax-...
