"after downloading installation files"
Where did you download it from?
Why do you say "files"? The TurboTax download is only one file.
"w/ virus protection & Wifi disabled"
You probably need an internet connection in order to install. Try not disabling Wi-Fi.
If you still need help, tell us exactly what happens when you try to install. At what point do you have a problem? If you get an error message, what is the exact message?
