Return Values
If the function succeeds, the return value is nonzero. To determine whether the function adjusted all of the specified privileges, call GetLastError, which returns one of the following values when the function succeeds:
Value Description
ERROR_SUCCESS The function adjusted all specified privileges.
ERROR_NOT_ALL_ASSIGNED The token does not have one or more of the privileges specified in the NewState parameter. The function may succeed with this error value even if no privileges were adjusted. The PreviousState parameter indicates the privileges that were adjusted.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
MSDN原文解释：
If the function succeeds, the return value is nonzero. To determine whether the function adjusted all of the specified privileges, call GetLastError, which returns one of the following values when the function succeeds:Return code Description
ERROR_SUCCESS The function adjusted all specified privileges.
ERROR_NOT_ALL_ASSIGNED The token does not have one or more of the privileges specified in the NewState parameter. The function may succeed with this error value even if no privileges were adjusted. The PreviousState parameter indicates the privileges that were adjusted.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
正确理解：这个函数返回为BOOL，明显TRUE则执行成功，FALSE则执行失败。一般的GetLastError是用在函数执行失败后的，而这个函数貌似很特殊，它通过GetLastError将函数成功时的具体结果（1，更改了所有指定的权限；2，还有一个或者多个权限没有得到更改）反映给调用者了@
