Why is my stopwatch not resetting?

using UnityEngine;
using System.Collections;
using System.Diagnostics;

public class GameManager : MonoBehaviour
{
	private static GameManager _instance;
	
	public string Quest;
	public Stopwatch time;
	
	public int player_money;
	public int Player_damage;
	public int player_xp;
	public int xp_req;
	public int player_armor;
	public int player_health;
	public int player_potions;
	public int player_armorpen;
	public int player_level;
	public float player_xp_modifier;
	public int boosterpacks;
	public string player_name;
	public bool dead;
	
	//Enemy stats
	public string monster_name;
	public int monster_xp_reward;
	public int monster_gold_reward;
	public int monster_damage;
	public int monster_armor;
	public int monster_armorpen;
	public int monster_health;
	public bool monster_dead;
	
	public static GameManager instance
	{
		get
		{
			if(_instance == null)
			{
				_instance = GameObject.FindObjectOfType<GameManager>();
				
				//Tell unity not to destroy this object when loading a new scene!
				DontDestroyOnLoad(_instance.gameObject);
			}
			
			return _instance;
		}
	}
	
	void Awake()
	{
		if(_instance == null)
		{
			//If I am the first instance, make me the Singleton
			_instance = this;
			DontDestroyOnLoad(this);
		}
		else
		{
			//If a Singleton already exists and you find
			//another reference in scene, destroy it!
			if(this != _instance)
				Destroy(this.gameObject);
		}
		time = Stopwatch.StartNew();
	}
	void FixedUpdate()
	{
		if(time.ElapsedMilliseconds >= 5000)
		{
			time.Reset();
			Save ();
			print("Saved");
		}
	}


	void Save()
	{
		//Super awesome save function.
	}
}

You have StartNew in the Awake so it is setting once. To reset you would have to call again somewhere else.