Once you have either unpacked a binary distribution, or built Csound from sources, you will need to configure Csound so that it will run properly on your system.
On Windows, make sure the directory or directories (normally the csound5 directory) containing the Csound executables directory and all the Csound plugin opcodes are also in your PATH variable, or else copy all the executable files to your Windows system32 directory.
On Unix and Linux, either install the Csound program in one of the system bin directories, typically /usr/local/bin, and the Csound and plugin shared libraries in one of the system lib directories, typically /usr/local/lib; or make sure that the directory containing the Csound and plugin shared libraries is in your LD_LIBRARY_PATH environment variable. This variable may have a different name in different operating systems.
On all platforms, make sure the directory or directories containing Csound's plugin opcodes are in an OPCODEDIR environment variable.