[Plplot-general] nmake install problem

[xiaohai w. <xia...@ho...>]

i am trying the command in https://sourceforge.net/p/plplot/wiki/Configure_PLplot_for_Visual_CXX_CLI/
( is it  correct to install plplot for c not only for c++ according to this  page?)<https://sourceforge.net/p/plplot/wiki/Configure_PLplot_for_Visual_CXX_CLI/>
for my c project in Visual Studio on windows to do the cmake

and after i typed  nmake install in command window throws a error like this

[100%] Built target x31
[100%] Built target x33
Install the project...
-- Install configuration: ""
CMake Error at cmake_install.cmake:44 (file):
  file cannot create directory: C:/Program Files
  (x86)/plplot/share/plplot5.15.0/examples.  Maybe need administrative
  privileges.


NMAKE : fatal error U1077: “.\cmake.exe”: 返回代码“0x1”
Stop.

返回代码  means "return code"

how can i solve this?
thank you in advantage