Why do you need to open your data files? Do you have them saved as pdf files?
Even if you reinstall the Desktop program, you will never be able to install and activate the 2019 program with the License Code. The License Code started in 2019. So 2019 needs to connect to Turbo Tax to verify the License Code. But they have stopped supporting 2019. They only support the last 3 years.
Do you need to save them as a pdf file? If you have old .tax files you can try converting them to pdf files at Www.Taxprinter.Com