The SetEnvironmentVariable function sets the value of an environment variable for the current process.
BOOL SetEnvironmentVariable(
LPCTSTR lpName, // address of environment variable name
LPCTSTR lpValue // address of new value for variable
);
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winbase.h.
Import Library: Use kernel32.lib.
Unicode: Implemented as Unicode and ANSI versions on Windows NT.
Processes and Threads Overview, Process and Thread Functions, GetEnvironmentVariable