Just now purchased a PC download of TT 2019 from Amazon. My Win10 notebook has a very small C drive and a micro SD card for D. D is where I (attempt to) install apps. The TT 2019 installer refused to install anywhere on D. Finally I launched a command window as Administrator and created a junction point:
mklink /J c:\TurboTax d:\TurboTax
Then I was able to tell the installer to use c:\TurboTax, and it successfully installed under d:\TurboTax.
After the first launch TT was unable to update itself, saying it didn't have access to the executable which it thought to be under the C drive. I did "Start->Add or Remove Programs->TurboTax->Uninstall" then selected the option to "Repair." After the repair completed I was able to update TT.
