download the client from: http://nsclient.org/nscp/downloads (choose the *.zip file) and extract it to c:program files%foldername%
Install the service from cmd:
c:program filesnsclient++-0.3.9-x64nsclient++.exe /install
Service NSClientpp installed…
NSClient++.cpp(233) Service installed!
then start the service with net start from cmd:
net start nsclientpp
The NSClientpp (Nagios) 0.3.9.322 2011-07-04 x64 service is starting.
The NSClientpp (Nagios) 0.3.9.322 2011-07-04 x64 service was started successfully.