The process is to download a CD image and then burn a CD to install from that CD. You can download from your "My Account" You can get all the way back to 1990

https://www.laptopmag.com/articles/mount-burn-iso-files-windows

Start by creating your program folder C:\Lacerte\00tax and  C:\Lacerte\01tax etc and copying the appropriate prep file to it. Then run the install from the CD Created. 

Come back if  you have problems.