Step 1. Go to the Control Panel and click on "Administrative Tools".    
   

Step 2. 

Now that you are in that section, click on "Services".
                

Step 3. A menu now appears with a listing of choices. Click on "Messenger".
   
   

Step 4. Messenger Properties: Change "Startup Type:" by dropping down the menu from "Automatic" to "Manual".

Step 5. Now that the "Startup Type:" reads "Manual", then click on "OK".
 

 Step 6. No more Messenger Popups now!