Having an issue importing DLL into unity - unity3d

Question

I'm trying to get the user32.dll into my unity FREE version. (Not pro)
I simply dropped user32.dll into my Assets/Plugins/ folder and the error it gives me is:
DLLNotFoundException: Assets/Plugins/user32.dll
Here is the code I am using:
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Runtime.InteropServices;
using System;
using System.Diagnostics;
public class DatabaseManager : MonoBehaviour
{
//DLL imports
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool SetForegroundWindow(IntPtr hWnd);
static Process proc = Process.GetProcessesByName("firefox")[0];
IntPtr ptrFF = proc.Handle;
//------------------------------------------------------------------------
void Awake()
{
SetForegroundWindow(ptrFF);
}
//Other code functions like Update etc.
}
I heard somewhere that unmanaged dlls (c++) can only be used in Unity Pro, but I really need this DLL, am I doing something not accurate??? I am not sure if user32.dll actually falls under an unmanaged c++ dll.
Please help.

Answer 1

Change the path from Assets/Plugins/ to Assets/Plugins/x86_64/.
using UnityEngine;
using System.Runtime.InteropServices;
public class DatabaseManager : MonoBehaviour {
[DllImport("user32.dll")] static extern int GetForegroundWindow();
[DllImport("user32.dll", EntryPoint="MoveWindow")]
static extern int MoveWindow (int hwnd, int x, int y,int nWidth,int nHeight,int bRepaint);
void Awake()
{
int handle = GetForegroundWindow();
Debug.Log(handle);
int fWidth = Screen.width;
int fHeight = Screen.height;
// Move the Unity windows.
MoveWindow(handle,0,0,fWidth,fHeight,1);
}
}