Here's what worked for me. From your install directory, open the "turbotax 2020" directory. Now run "turbotax 2020 installer.exe". The install started without issue, completed as it should.
I surmise the setup.exe requires the 2gb minimum before poceeding to "turbotax 2020 installer.exe". My hp envy x10 has the atom 32gb processor with soldered in 2gb ram and win10. Hopefully, it will install on your similar notebook.
