by "Upgrade" do you mean a new computer or updating your current OS?
if just an OS update from 10 to 11, there is a provision to revert back to 10 see this link
https://www.msn.com/en-us/news/technology/how-to-downgrade-from-windows-11-to-windows-10/ar-AAPyZSd
however, this is a temporary fix. sooner or later your old computer will not be compatible with future versions of windows. for me No TPM and older CPU means, I can't update to 11
with a new computer even with the CD's to install older versions, assuming they'll install at all, what you have is a beta version of the program that does not reflect the tax laws for that year. As of now, no updates are available for years before 2018 and no state returns for those years. TT only supports the current year and 3 prior years. if you install, say 2013, and open the .tax2013 file the return will change to reflect the beta program and not the return you filed.
