The NI download page doesn't offer Runtime versions prior to 2009. But their FTP site still exists and has them.
ftp://ftp.ni.com/support/labview/windows/runtime/7.1/LVRunTimeEng.exe
This is the latest released 7.1.1 runtime version. In a subfolder in that directory is also the 7.1.0 version but you should not need that.
That all said, this installer was created about 5 years before Windows 7 was released. It could not even guess how Windows 7 will look like so if it installs that's your luck, if it doesn't well you have no guarantee and support in that respect. It did install in a Windows 10 Test VM here.
Most browsers nowadays do NOT support FTP access anymore. It's not even disabled but simple not there, nada, nyet, nix! I recommend a client like WinSCP to access FTP sites.