Thank you for the interest in NodeXL!
Please have a look at this thread:
And this thread, which may be related to your issue:
Please try this:
In Windows Explorer, navigate to C:\Program Files\Common Files\Microsoft shared\VSTO\10.0.
In that folder, you should find a file named VSTOInstaller.exe.config. Rename it to VSTOInstaller.exe.config.old. (Ignore the warning from Windows about the file becoming unusable.)
Run NodeXLExcelTemplate2014Setup.exe again.
Does that fix it?