Nagios Support Forum

I have tried the examples of the link you have sent but still getting some errors. See attachments.

I'm a little stumped as to why that wouldn't be working, I'm comparing what you've got vs the documentation for external scripts, and it seems to be consistent. The only thing I could see that might be worth trying is uncommenting the script_dir directive to the nsc.ini.
script_dir=c:\my\script\dir

If that doesn't fix it we might have to defer you to the NSClient forum. The issue appears specific to the nsc.ini configuration.
http://www.nsclient.org/nscp/discussion/forum/1