Dependencies for Windows NT4
Since windows NT4 is OLD (yes it is really old and you should think about upgrading) it has some dependencies which I have decided not to resolve easily. This means you need to install some Microsoft components to get tings up and running on Windows NT4.
Hopefully this should not be to hard and not cause you any problems.
PDH library (CPU, memory, etc etc)
NT4 does not come with the PDH library and you need to install that before using NSClient++. PDH can be downloaded from Microsoft: http://support.microsoft.com/default.aspx?scid=kb;en-us;Q284996 and the simplest way to install it is to uncompress it directly into the NSClient++ directory.
PSAPI (process checks)
NT4 (sometimes) lack the PSAPI helper which is available in the "Platform SDK Redistributable: PSAPI for Windows NT" from Microsoft. http://www.microsoft.com/downloads/details.aspx?FamilyID=3d1fbaed-d122-45cf-9d46-1cae384097ac as with the PDH either install in system32 or local NSClient++ directory.