I think, you misunderstood what I wrote:
I'm not talking about Native Access or Service Center.
Go to NI's
website and log in to your account.
Your products are listed there with the option to download them.
Newer products (normally installed/updated via Native Access) come with a "Downloader.exe" to download the instrument in a second step.
The "Downloader.exe" provides "Download" (only) and "Download and Install".
Older products (installed via Service Center) are also manually downloadable from this site/your account.